Unlock the mysteries behind the cables and connections that power our digital lives with Nokia Bell Labs' Xi (Vivian) Chen and Fatima Gunning, from Tyndall National Institute. This episode promises a fascinating exploration into the world of high-speed optical fiber communications—a vital yet often overlooked cornerstone of modern technology. As we journey from the switch from copper to the latest in fiber technology, you'll discover the incredible engineering feats that allow you to stream, browse, and connect at the speed of light.
Join us as the experts also discuss topics like the transition from materials like lithium niobate to the realms of silicon photonics and indium phosphide—all pivotal in our quest for faster data transmission. Further conversations are had on the challenges of adapting these technologies to new fiber types and how innovations like multicore and few-mode fibers could redefine the landscape of global connectivity.
However, the chat isn't just about bits and bytes; reflect on the values that underpin successful leadership in science and the fresh perspectives brought in by emerging talent. By the end of this episode, you'll be looking at the tangle of cords behind your desk with a newfound reverence for the photons racing through them and the people behind the innovation!
Host:
Thierry Lapinte-Leclerc
PhD Student
Boston University, USA
Moderator:
Fatima Garcia-Gunning
Senior Staff Researcher
Tyndall National Institute, Ireland
Expert:
Xi (Vivian) Chen
Department Head, Optoelectronic Sub-systems
Nokia Bell Labs, USA
Unlock the mysteries behind the cables and connections that power our digital lives with Nokia Bell Labs' Xi (Vivian) Chen and Fatima Gunning, from Tyndall National Institute. This episode promises a fascinating exploration into the world of high-speed optical fiber communications—a vital yet often overlooked cornerstone of modern technology. As we journey from the switch from copper to the latest in fiber technology, you'll discover the incredible engineering feats that allow you to stream, browse, and connect at the speed of light.
Join us as the experts also discuss topics like the transition from materials like lithium niobate to the realms of silicon photonics and indium phosphide—all pivotal in our quest for faster data transmission. Further conversations are had on the challenges of adapting these technologies to new fiber types and how innovations like multicore and few-mode fibers could redefine the landscape of global connectivity.
However, the chat isn't just about bits and bytes; reflect on the values that underpin successful leadership in science and the fresh perspectives brought in by emerging talent. By the end of this episode, you'll be looking at the tangle of cords behind your desk with a newfound reverence for the photons racing through them and the people behind the innovation!
Host:
Thierry Lapinte-Leclerc
PhD Student
Boston University, USA
Moderator:
Fatima Garcia-Gunning
Senior Staff Researcher
Tyndall National Institute, Ireland
Expert:
Xi (Vivian) Chen
Department Head, Optoelectronic Sub-systems
Nokia Bell Labs, USA
Illuminated by IEEE. Photonics is a podcast series that shines light on the hot topics in Photonics and the subject matter experts advancing technology forward.
Speaker 2:Hello everyone, welcome to today's episode of Illuminated, an IEEE Photonics podcast. My name is Thierry La Pointe-Leclère and, as the IEEE Photonics Society Emerging Technology Task Force representative for the Young Professionals Program, it's my pleasure to be your host today, I guess. Before getting any further, I would like to introduce myself, because all of you will be unfamiliar with who I am not that I blame you so I basically am a first year PhD student at Boston University, working in Professor Siddharth's or Mashantran group, who specialize at the moment in optical orbital angular momentum beams. I have a master's degree in photonics from Laval University and a bachelor's degree in engineering physics from the same university. I think it's fair at this point to say that I enjoy the field of optics in Photonics quite a bit, because I've spent already at least like seven years working in various groups and on various projects in Photonics and I'm absolutely delighted to be hosting this episode of Illuminated.
Speaker 2:So on to today's podcast. This one is particularly interesting because we're looking at how we keep finding new ways of sending more information and at faster rates in optical systems. In particular, we're going to be discussing high speed optical system and high throughput fibers, and our expert yesterday is Viviane Cheng from Bell Labs and our moderator is Dr Fatima Gunning from Tyndall National Institute. We will go into their technical work, career journeys and advice for young professionals. Well, thank you for listening to this episode. I think it's going to be a good one. First of all, I'd like to introduce Fatima. I'll give a brief bio.
Speaker 2:So Fatima received a PhD in Opto-electronics in 2000 from Pontifica University at Catalica de Rio de Janeiro I hope I said that correctly Investigating fundamental optical properties of glasses, chemical fibers and planar waveguides transformed by a technique called thermal polling. As a postgraduate researcher student, or as a postgraduate research student, she visited British Telecom Research Laboratories in the UK and joined Corning Research Centre at Adelstral Park, also in the UK, in 2001 to work on advanced electroabsorption based optical modulators for applications in high speed optical transmission networks. She co-founded the Photonics System Group at Tyndall National Institute in Cork, ireland, in 2003. There are research focuses on spectrally efficient techniques for high speed optical transmission, including all optical OFDM, coremwdm and frequency comb generation, expanding communications to new wavelength windows, namely to micron, and with fibers such as OOCOR fibers. She actively works closely with Photonics Devices integration and packaging teams to enable next generation components for communications.
Speaker 2:She was at IEEE, so her role within IEEE Photonics Society over the years have involved being a VP of Multicultural Outreach from 2018 to 2019 and VP of Membership Outreach for the IEEE Photonics Society from 2020 to 2022. And even though right now I don't see a position listed, an official position, she's still very active within the society, being a volunteer through mentorship, conference committees and co-hosting events, so I think she's probably quite busy.
Speaker 3:So thanks, Therese, for the introduction. It's a delight to be here and it's in delight to introduce our guest speaker today, which is Vivian Cheng. Vivian Cheng is a distinguished member of technical staff and department head of Optoelectronic subsystems group Anoka Bell Labs. She received her PhD degree on optical fiber communications in 2012 from Universal Melbourne in Australia and from 2013 to 2015, she was a research fellow at the Universal Melbourne conducting research on optical fiber transmission and since 2015, she's now she has been in Bell Labs since then with current research interests including advanced digital signal processing and high-speed fiber transmission. She was a awardee of the Young Investigators Award in 2020 for Atropical Electronics Society and she's a senior member at Tripoli, a fellow of Optica, and she published more than 150 papers in the era of high-speed optical fiber communications well over 60,000 citations. So it's super exciting to have you here, Vivian. Welcome to this podcast.
Speaker 1:Thank you, thank you Fatima, thank you Teri. It's great to be here, so hopefully today we talk about what we're doing in terms of fiber communication and high-speed optical transceivers and share some of our thoughts and discussions, and hopefully that would be interesting.
Speaker 3:Yeah, that's great, and then it's very interesting, I think, about a couple of years ago at the UFC. We talk about 50 years of using optical fibers and so on, but it took a long time for people to move from copper to optical fiber. So what is it that you're doing in terms of what is it that? Optical fiber? Sorry, let me start again. Sorry, let's start again. I said something else and I just shouldn't have said so. We heard a couple of years ago back in the UFC the 50 years of optical fibers. It was super exciting to see that happen. It took a long time for people to really install fiber on the ground and people have been moving from copper to fiber, maybe started with submarine systems and long-haul systems, but now even coming closer to people on access and to their homes. So where do we see optical fiber installations and what is it? Optical fiber transmission? What are we talking about?
Speaker 1:Okay, that's a good question. I don't think you necessarily see optical fibers in daily life, although everyone of us most of us using them all the time. So they are basically buried in the ground. If we're talking about terrestrial links, that's the technical term we use. So they are buried a few meters down to the ground or they are literally sunk into the bottom of the ocean.
Speaker 1:It's not like wireless communication, like your phone. You will see the base, towers, a tennis around you. You don't really get to see those, but I would say 99% of the distance your signal is transmitting through the media is not really air, it's fiber. And so, for example, if you make a phone call from the US to Europe, china, india, any other country, it's only the first maybe 10 centimeters that your signal transmitted from your phone. That is through air, which is wireless, and then, starting from the point that antenna got your signal, everything most likely is only fiber. And then it gets to the other end and another antenna is transmitting your signal to another phone and that's another very little part that is not fiber, and everything in between is most likely all fiber and they are in the ground or at the bottom of the ocean.
Speaker 3:I see, and why do we need research? Then? Optical fibers, what is it? The challenges associated with installing the fiber on the ground or making those transmissions and converting between wireless and optical, I mean what are the challenges? Here, yeah.
Speaker 1:So the challenges, as we can probably imagine, the challenge is we need more speed, we need more data and we need more bandwidth. And if you think about it 20 years ago, what kind of phones we have and what kind of applications we're able to do with our computers and phones, and that amount of bandwidth compared to the bandwidth we're consuming today, that's the factor of depending on the application it could be a few hundred times or a few thousand times increase. So that's a huge change in terms of what we demand in terms of bandwidth. And so if we take that perspective and think about the future, in the next 10, 15, 20 years, what we would need, if you don't think about the past and just standing now and try to imagine what we might need and you tell people, oh, I think we need five thousand more times of bandwidth for the next 15 years, people will probably see this might be crazy because how can we need so much more? We're pretty good in terms of bandwidth and speed, but if you think about the past and ask people, if you imagine you ask people on the street 15 years ago, you think you need this much bandwidth today and they probably think you're crazy.
Speaker 1:So I always thought, even for people who work in technology, even in the field of telecommunication, they might underestimate how much bandwidth we may need in the future, and the data sets so too. If you look at the data, there's solid data saying every year we are demanding about 50 to 60% more data. So that's the annual growth of 50 to 60%, and that's a lot. If you take that number and do a 10 years projection, you are looking at about 100 times more bandwidth. So that's the challenge we need to scale our electronics and optics fast enough to satisfy the demand, and so what we want to do is higher bandwidth, more throughput at a reasonable price, and we don't use all the energy in this world, so power consumption is also very important. So that's the main challenges.
Speaker 3:So how can be done? So your research says that you're working with transceivers and you're talking about increasing bandwidth, make higher speeds using less energy. So what is it that is consuming this energy and how does this transmission work? Yeah, okay.
Speaker 1:So let's start with. What do we mean by bandwidth? There are two bandwidths that are relevant here. One is the bandwidth of the fiber itself. So if we take a step back the fiber transmission system on the high level, you only have three things. You have a transmitter that is sending the light, that carries information, and then you have a fiber link that's connecting your two points and then you have a receiver. So when we talk about the bandwidth of the fiber, that's about four terahors bandwidth, or roughly 35 nanometers bandwidth. That's a lot of bandwidth, and this whole fiber typically nowadays depends on the application and also distance.
Speaker 1:This fiber can carry about anywhere between 20 to 40 terabits per second. So one terabit is 1000 times of. Say, if you have one gigabit per second for your home, this is one terabit is 1000 times of that, and 20 to 40 is 20,000 to 40,000 times that. So this is what a typical fiber can carry. And then you have your transmitter and the receiver and you have the bandwidth or the throughput, or sometimes we call interface range, of your transmitter and the receiver, and that's a much smaller bandwidth. So typically you have anywhere between 50 to 100 gigahertz bandwidth, depending on whether you're talking about product or research, and that gives you about one terabit or two terabit per second data rate. So you typically need anywhere from 30 to 40 of them to fulfill the whole bandwidth of the fiber. And so when we talk about increasing the bandwidth, for the part I am working on, I mostly work on increasing the data read or the bandwidth of the transmitter and receiver, and after you increase that, you still need multiple of them to fill the bandwidth of the fiber. So part of our research is on how to develop better transmitters and receivers that carries more information per transmitter. And then some other research groups or my colleagues or other people, they are working on how to develop better fibers, a fiber that can carry more bandwidth. So those are the two main parts and for my research, for the transmitter part, back to the question how do we make transmitters that carry more information or more data right? Then we need to dig a little bit deeper on how transmitter works.
Speaker 1:The transmitter on a high level only have three things. It starts with a laser. So the laser we are using for telecommunication is a laser. We call CW laser, continuous wave laser. So that means the laser is sending out light constantly. It's a constant power and the light that is constant or any electromagnetic wave that is constant doesn't carry information. So, despite this, for people who are not necessarily familiar with telecommunication, imagine your city light or you have a flashlight at torch and you turn it on. That light is always on and it doesn't carry information. However, if you start to dim the light or flash the light according to, for example, a mask code, then the light starts to carry information and the process you use your hand to change the on and off status of the light. This process is called modulation. So the same thing happens in an optical transmitter. You start with a laser and that light doesn't carry information, and you send the laser into a device that is called a modulator. So this modulator takes to input. It takes the laser, it also takes the electrical signal and this electrical signal is your data or your information, or you can say that's your zeroes and ones. So the modulator starts to manipulate the light properties, for example power of the light, according to the electrical signal that is added to the modulator. And then the output of the modulator is a. You can see that as a light that is being manipulated or dimmed or flashed to some extent, and that light starts to carry information. So that's how the transmitter works.
Speaker 1:And in order to make a transmitter that is fast, you need basically two things. That is fast it's not really the laser. The laser is sending out constant light and the laser we're making today, especially the laser we make for high end optical transmitters they are good enough in terms of the performance. We are more working on how to reduce the power consumption, how to reduce the form factor and all this, but not the performance itself. In order to make a faster transmitter you don't necessarily need to do much on the laser itself. You need two other things that works fast, that is, your electrical signal generation and the modulator.
Speaker 1:So a lot of research and innovation are done on this two part to push the speed of this two. For example, for the electrical signal generation, for decades we were relying on the CMOS technologies, and when the CMOS node gets smaller we get faster gates and we have faster electrical signal generation. That's how we have faster electrical signal to drive the modulator. But the speed that CMOS is scaling is clearly not quite enough for the speed we need for the transmitter itself to scale. So some of the researchers start to do something outside the CMOS. They take other materials, for example, in a phosphate or silicon germanium, they combine multiple CMOS signals to form a higher speed one so that you can you will not only be relying on the CMOS scaling speed and you can do double or triple speed compared to the CMOS speed, and that's one of the ways to do higher speed. Electrical signal generation.
Speaker 1:And then, in terms of modulator, we are mostly relying on materials. For a long time, starting from, we widely deploy optical transmission links, especially coherent transmission links. We were using a material called bulky lismai bit material for modulator and that's an excellent material. The only problem is is not fast enough for today's modulator. So nowadays, in the past maybe five to seven years, there has been a lot of innovations on making new materials.
Speaker 1:That is faster and also much smaller informed factor to make modulators. And at the moment what product is using very widely is either silicon, photonics or in a phosphate and they are faster speed, so they make higher bandwidth modulator. Therefore you can, you can make higher speed transmitted out of it. And there are also a lot of very promising material in research domain. For example, one of them would be some families and I bet they are kind of they're similar to traditional is not admit, but much faster speed and much smaller in terms of form factor. There are other very innovative materials like organic materials or post money and all this. They're all under research. But for modulator itself mostly we rely on the material innovation. That's the two main area people are doing very active research on to try to bring up the speed of an optical transmitter.
Speaker 3:That's very interesting. That's on the speed, but the other thing you're talking about is throughput. How can we increase the overall fiber throughput using those new devices that you're talking about?
Speaker 1:So throughput of the fiber doesn't necessarily get increased because the transmitters are faster. So, as I said, fiber has a certain bandwidth, so the transmitter has a much slower bandwidth, smaller bandwidth than that. So we need multiple. The reason why we push each transmitter to higher speed is we want to use less number of transmitters. That's better, because laser is very expensive. Every transmitter comes with one laser, so at the moment the laser is not cheap enough. It's a significant cost to each transmitter. So we try to use less lasers, which means each laser has to carry more information. That's the main motivation why we're pushing the per transmitter speed to as high as possible. But when it comes to the throughput of the fiber itself, the most widely deployed fiber now is called standard single mode fibers and we're using about 35 nanometer of the fiber. The fiber support more than that but amplifiers doesn't. So we're limited by the optical amplifier bandwidth and that's what we call the conventional band, the C band. It's about four carats or 35 nanometer.
Speaker 1:In order to have more bandwidth from the fiber or more throughput from the fiber, there are several things you can potentially do. You can extend the bandwidth of the fiber itself because the fiber does have a very wide low loss window and you can try to develop other amplifiers that support more bandwidth. That's one way to do it. You might get a factor of two, three or even more out of that and the system quickly gets pretty complicated because every band you have to use different amplifiers. So when an optical signal, a very broad optical signal, gets to a point that it needs to be amplified and by the way that's dependent on the transmission link that's anywhere between 50 kilometers to 100 kilometers. So if you have a link that is between, say, europe and here, then you need many, many amplifiers. I mean the summary links is anywhere between 10,000 to 8,000 range, so you need a lot of amplifiers. So every time you need to amplify a signal you have to split them into different bands and amplify them through different amplifiers and combine them. So it is a less scalable way if you try to increase the bands or the useful wavelengths out of fiber.
Speaker 1:The other way to do it is to just add more fibers. So you can either add more fiber in the way that we call fiber bundle, so simply have more fibers there, or you can use more noble fibers. For example, you can use multi core fibers, which means single mode fiber has one cladding with one core in it. You can have one cladding with multiple core in it, for example three or five or seven or even more. Or you can use something called a few mode fiber. So the single mode fiber.
Speaker 1:As the name suggests, it supports one mode. You can make fiber that has more than one mode, for example three or six or 15. And in that way you have more modes, which means you can do multiplexing by effect of number modes. Or another very interesting type of fiber is the fiber we call holocore fiber, so it's air in the middle. It naturally supports much more bandwidth, much more wavelength range than single mode fiber. And it is possible to develop one amplifier that supports wider bandwidth than single mode fibers C-band amplifier, that's also one way to do it. And all these are very active research domain in fiber fabrication and also system transmission link as a whole, and those also affect our future projection on how an optical transceiver will look like.
Speaker 3:I see, and Teri, do you want to ask a question?
Speaker 2:I don't want to step on what you were going to ask, but I did have one related question to what Vivian was discussing.
Speaker 3:Yeah, you can ask a related question. And then I was going to go and ask something else. I wanted to go into digital signal processing. So if it's related, just ask the question.
Speaker 2:Okay, perfect. So I guess what I wanted to ask also is now you brought up different architecture for fibers, right? So multi-core, multi-mode, holocore, and you said you've been looking into possibly going in those directions. How does that? How challenging is it to adapt your optical transceiver design for different types of fibers?
Speaker 1:That's a great question and principle, does not? You can okay, let me put this way. You can use the current transceiver for some of the new fibers, for example. If we are talking about fiber bundles, then basically you don't need to change anything. You just put more transmitters and receivers there. They're parallel, they are independent. Or for multi-core fibers, then it depends. If the core couples to each other, meaning there are crosstalk or on a system level we may call it information exchange among the cores, then your receiver should design in a way that it can deal with the crosstalk, and that's a typical process we call the MIMO processing. So you need to process all the signals from all the cores at the same time. To redo the crosstalk Multi-core fiber, then sorry, a few more fiber, then you do need to have a new set of signal processing. The hardware wouldn't necessarily change much, but it's the digital signal processing party to whether you need to deal with the coupling between different dimensions that you're using now.
Speaker 3:It's interesting because that lists the way that I was thinking on the digital signal processing side. So I suppose not all signals are perfect and there's lots of impairments and, as you said, crosstalk that might occur. So explain to us a little bit on the work that is needed on digital signal processing, perhaps not only the receiver but sometimes even at the transmitter as well.
Speaker 1:There are a few important pieces in terms of digital signal processing. So all we talk about at the moment we are talking about high-end optical transceivers. That means the transceivers are developed for long-haul distance transmission and that means we are using, we are using, we're trying to use the bandwidth very efficiently, and that means the transmitter usually have one important digital signal processing that is called pulse shaping. The name sounds very confusing, but basically what it does is it tries to squeeze the information into a bandwidth that is theoretically as small as possible and you try to shape your spectrum in a way that it theoretically cannot be smaller enough. That means you are using your bandwidth the most efficient way, and that's a processing. It's a digital filter. It's a digital linear filter that we use as transmitter to try to increase the spectral efficiency, basically, and both the transmitter and receiver also have error correction. So that means you typically add about 20 to 25% overhead in terms of error correction, coding, and that's the part to protect your signal from noise and distortions and to recover your bits without errors. And then. So error coding and pulse shaping are probably the two very important part of the transmitter processing. When it comes to the receiver, it's a little bit more process because the signal now propagates through a long fiber channel and it has experienced a lot of distortions and noise. So the receiver, what it does, is basically try to undo whatever happened in the channel, and there are a few important pieces there.
Speaker 1:For fiber there is chromatic dispersion and that means every wavelength or frequency of your signal experience a different delay and your digital signal processing needs to undo that. Basically, it's a phase profile that you add to your signal to do the reverse of what the digital and what the chromatic dispersion has done, and then after that you need to compensate the crosstalk. Even for single mode fiber, there are two polarizations that we're using. They are orthogonal so but the way you receive it they are mixed, because your projection of the two polarizations cannot be the same as how you send it at the beginning. So it has been rotated. It's a unitary matrix if you use a two by two matrix to describe that.
Speaker 1:So your receiver has to figure out what kind of rotation has been done and then rotate it back, basically to separate your two orthogonal positions. And it also needs to be able to track, because your fiber is not in the in a very static environment. There is mechanical vibration. There are other things. That is keep changing. So your receiver needs to be able to track the rotation over time and keep correcting that.
Speaker 1:And after that, there is a laser difference between the transmitter and receiver. They are the transmitter has a laser, the receiver has a laser. These two lasers have slightly different frequencies. They cannot be aligned because they don't talk to each other. So the receiver has to figure out what's the difference between these two and compensate that. And the laser also have face, and face is a noise is random. So the receiver also needs to be able to estimate how much face difference between the two and being able to compensate and track that. And then, after it goes through all those processing, the signal, should go back to what you sent at the transmitter with noise, and then you make a decision and do the error correction. So that's the important building blocks of transmitter and receiver digital signal processing.
Speaker 3:Yeah, that's. That's extremely fascinating and how things have evolved. But you also spoke about as working with transceivers. One of your. One of the important boxes that you also need to take is the energy efficiency. So I suppose the fiber is passive, nothing happens there, so the energy consumption is coming from your transceivers, and maybe the optical amplifiers as well, obviously. But you know what is the effort that is required in order to make that receiver increasing speed, increasing data rate, better digital signal processing, and yet you have to market on the energy efficiency. How is that possible?
Speaker 1:Yeah, it's hard. It's hard so once in a while. Yes, fiber is passive, but how does fiber relate it to power consumption? Fiber has loss. So although it's passive, if it has a lot of loss, then you need a lot of energy to boost the signal back. So one of the important progress in fiber fabrication in the past many decades is to reduce the loss. So nowadays fiber is pretty good in terms of loss, but that's also part of the energy reduction there. If you have a lower loss fiber, you need less powerful amplifier. Then you save energy. So now let's look at the transmit and the receiver.
Speaker 1:I wouldn't say there's one single thing you do to reduce the power consumption. It's a combination of pretty much everything, from the hardware design, from the laser design and from digital signal processing. When we talk about digital signal processing, a major factor is battery, cmos, which means smaller nodes and consumes less energy, and also the algorithm itself. You need to be able to design the efficient algorithm that does a good job but doesn't have a high complexity. That's important. And you need to find modulation format that is more efficient for the limited amount of power you're using.
Speaker 1:And when it comes to hardware, laser is getting more efficient these days and the modulator now is much higher bandwidth. Or the other way to look at it is actually much higher bandwidth. It actually means it needs less driving voltage. So the progress we made on designing a better modulator is also a relatively big factor on why we are having lower power consumption devices. And on top of all this there are a lot of progress made on electrical amplifiers and circuits that are making things much smaller than before. So that means the electrical traces on the device is much shorter and that means less loss and higher power efficiency. So it's a lot of hard work from pretty much everywhere to try to reduce the power consumption.
Speaker 3:Oh, I can see that that's something that we're going to continue to work for a few years.
Speaker 2:Yes, Come, Thierry you have a question. So the group I'm in right now work on OAM beams, right? So I guess we mentioned the multicore fibers, multimode fibers, and one of the challenges for energy efficiency right now, if we switch to the schemes, is the use of the algorithms. The digital signal processing like MIMO is very effective, but it's also very Not inefficient. I think it is efficient but it will consume some power. So I guess the question would be are there schemes such as OAM beams that eliminate, at least in part, the need for algorithms like MIMO, that you take out potential in the future?
Speaker 1:Yeah, that's a great question. So one way people tend to go to is try to eliminate crosstalk between modes and cores as much as possible. My personal view, first of all, if we are talking about high-end long-distance applications, the transceivers for those MIMO is not a part that is very heavy in terms of power consumption. So even if we don't do any MIMO I don't really have numbers in my head but we're not necessarily saving a lot A lot of power is consumed by number one, chromatic dispersion compensation and number two, error correction. That's a very big part of the whole power consumption in terms of digital signal processing. But it can be a problem if your MIMO size gets too big.
Speaker 1:I wouldn't say it's a problem if you have three modes or five modes, but if you start to have 15, 20, or even more, number one needs to look into how to implement that in a efficient way. And if you try to eliminate all the crosstalk, then I guess it's a good idea to look at overall are we saving in terms of performance Some of the fibers? It works better if you have crosstalk because when you start to randomize the signal in different chords or modes, it averaged some of the non-linear effects and that gives you some sort of advantage. So it depends on the application If you're doing long-haul, short-haul, how much DSP you want, or do you want DSP at all? And we should always start with the application and what we're sensitive about for that application.
Speaker 2:Thank you, that's very interesting.
Speaker 3:Yeah, it is very interesting. And the final question that I have on the current devices and systems is on energy. Is there any role for safe photonic integration there? Does photonic integration helps with energy consumption or does it help with the footprint or, as you said, a combination of things?
Speaker 1:Yeah, integration helps with everything. I would say. It definitely reduces the form factor, which is very good, and it most likely helps a lot in terms of power consumption because when things are smaller, transmission distance are shorter and you save loss and also you can design your impedance in a different way. It opens a lot of possibilities and, honestly, for the future, if we think about we are going to need, if we just project the 50 or 60% annual growth, we are going to have probably 100 times actually more than 100 times more interface rate in 10 years range. And if we do look at how fast we're scaling the interface of a single transceiver, it is about 20%. So you see the big discrepancy between the two.
Speaker 1:So very, very likely at some point we will need to put multiple transmitters in one package and nowadays we are seeing signals from one transmitter as an entity and then if you have a terabit signal here, you treat this as a single, independent piece of spectrum. You add and job and send it to different receivers, but maybe in 10 years range you always need to treat 10 of them as a group because no one wants one of this, one terabit or 10 terabits. I need much more than that, so there's no need to separate them at any point of your network. Then you will put all the hardware together, and then, when you have 10 or 20 transmitters in one package, you need some innovations on how to integrate them and you need to make them small enough so that they fit whatever form factor you need to plug this thing to and you also need to Well, you have a lot of them in one package.
Speaker 1:You probably cannot tolerate a lot of electrical interface and then convert signal to a certain socket and then use another socket to connect it. It's just not practical. So integration is the way to go, more integration. We're doing a lot of integration these days already, compared to 10 years ago. It's fascinating how small things get to and how many layers you see in terms of one Inside one, one small little package. But we're going to do more, I'm pretty sure.
Speaker 3:And I think I have a final question here in terms of research and your work. So what does the future hold and what is it that you're working at the moment in research that we are going to see implemented in the next, say, three, five, 10 years time?
Speaker 1:I think that's something we touched upon a little bit already.
Speaker 1:I think we are going to do more integration, and that opens up possibility of design things structurally in a very different way.
Speaker 1:So integration doesn't necessarily mean we just put 10 of them or five of them in one package and make them as small as possible, and it's very likely we're going to see a different ways of putting them together so that we have a jump in terms of either energy efficiency or performance and maybe we design our signal processing in a very different way, because now you have 10 channels in one package and you may want to see how can I come up with a brand new digital signal processing method that can compensate some hardware defect that was not able to be addressed before?
Speaker 1:And how do you design your signal processing together with hardware design? Will that help and make the overall global performance much better than many of the independent one just simply put together? So that's something we are thinking about for now and besides that, I guess it's just we're trying to see how to have higher electrical signal generation and at the same time keep in mind that is the power consumption still makes sense? Is the cost still makes sense? Do we want to think things very much outside the box and doing something very different from now. That's things we're actively thinking about.
Speaker 3:Thank you, vivian. It's fascinating to see that, when we had to look at those problems at a more systems perspective, network perspective, rather than the just individual components alone, because it's the sum of them all that is making a difference, I suppose, for, as I said, efficiency, energy efficiency or even cost, is that true? Yeah, exactly.
Speaker 1:So I think the more developed this field it's like maybe many other fields, you need people who understand pretty much everything. So in 10 years, 10 years ago, 15 years ago, people are making transceivers. People are very specialized. If you are a device person, then you design a laser, you design a modulator, a photo diet, and you are very good at that, and you don't necessarily know much about error correction or digital signal processing. And people who do DSP, they don't necessarily have to understand the device. They know on a high level how they work and that's all.
Speaker 1:But nowadays it's getting more and more obvious that we need people who understand more than that small thing that used to be a standalone thing. And if you know the whole picture, if you are doing signal processing and you understand what are the limitations of your devices and why those are limitations and how hard it is to overcome that limitation, you might start to think, oh, if this is so hard and hard, well design, can I do something in the signal processing? Is that easy overall? And so this is getting very interesting. We will see people who can handle the same studies outside a smaller topic probably can come up with very clever ideas and we might be surprised about their solutions. We'll see.
Speaker 3:Yeah, thank you, thank you. Thanks a lot, vivian. Thank you, I don't want to be deleted from this, from to be added out, but the comments are the following I made this question on purpose because, depending on the audience, they might be working, say, on devices, or they might be working as a signal processing, and your answer was perfect. It's exactly what I wanted to hear. So for them to see that you had to understand a lot of stuff. Excellent, I love that. Thank you. Sorry, teri, I'll pass it on to you now.
Speaker 2:Oh, thank you so much. It was super interesting and I guess it ties into the fact that since it's ever relevant field, right for 100 years and more now telecommunications has been a field where a lot of interesting research has been done, and I guess now some young professionals might be interested in getting into that field and they couldn't be better served than by asking questions to someone like you. So I guess the next part would be to ask you a little bit of career advice for anyone who would be interested in getting into that field. I guess the first advice you.
Speaker 1:That is pretty interesting, so ask.
Speaker 2:I guess the first piece of advice already that you've given is to be good at multiple things within that field. So study your DSP and study fibers, study sources, electronics. So the first question I had wasso you've talked about a lot of the development of optical transceivers, fibers, all those things. So, and from my understanding also, you do both work in the lab also as probably some simulation, theoretical work. But one thing that might be interesting is to share your thoughts on how do you run a good experiment? How do youbecause that's a big part of the development process, right?
Speaker 1:Yeah, Okay, Thank you. I guess in order to run a good experiment, you need to like doing experiments. I guess that's number one. If you have fun, you do a better job. I don't think people have to do experiments to be successful or doing good things. In telecommunication A lot of people are great in doing theory and also information theory that's a huge part of this and design modulation format and run really complicated simulations. So you don't really have to be good at experiments to make something good. And if you don't like experiment, I think that's fine. You can do simulations of theory and you will still be really good and produce very useful things for the community.
Speaker 1:But if you want to do experiment, I think for our experiment I would say in my experience I would say pay attention to things. That doesn't quite make sense. What I mean by that is when you get into the lab you probably have a goal. This is a system I'm going to build and then I'm seeing the result from the computer or a piece of equipment and maybe it already looks like what you're getting. You're getting what you want the signal, the data rate and you hit the required the bit to error ratio and all this.
Speaker 1:So you can probably already conclude the experiment at that point, but then you might have observed something that doesn't really make sense, something that you were not expecting. Maybe you observe something a little bit strange from your spectrum or during your signal processing. There are some response of a filter that looks a little not so normal. According to your past experience, Although you have done the experiment and you get all your data and you could write a paper about it already, I would say pay attention to those things and don't let it slip away, and make sure you understand as much as possible. And that always, sometimes surprisingly, leads to something that you never understood before and it's something maybe you realize no one has ever understood. So pay attention to small things, especially those that look like quite make sense.
Speaker 2:That's awesome, thank you. It's very interesting because that's something I've been told as well that science happens in the year. Sometimes the mundane details is where you find the very interesting things. So that's definitely like you see a little discrepancy and that's where you can go from.
Speaker 1:Right, right. Sometimes it's nothing, but sometimes you get a lot of joy understanding things that you didn't expect at all.
Speaker 2:That's fantastic advice, and I guess that ties into the next question, which would be is there a piece of advice, a specific piece of advice that you've received early in your career that has been very influential on your path?
Speaker 1:I wouldn't say it's a specific sad piece of advice, but what I've seen from my colleagues and people I worked with when I was studying and also later I'm working what I've seen that influenced me a lot are people, their passion, I would say the researchers around me. I see that when people really like what they are doing and they had a lot of fun and they genuinely like what they are doing they do a much better job, consistently and sustainably and also they are happier and they are producing better things and life is better that way. So I guess that's what I observed. And then I start to maybe constantly check with myself do I still like this? Am I having fun? And just make sure I still like what I'm doing and so far I like it very much and I think it's good. Yeah, I guess it's a passion. I see people around me I really like that and that has an impact on me for sure.
Speaker 2:And so being passionate is probably the most important thing. If you're happy at doing what you do, like you said, you're probably going to be much better at it and also you're going to enjoy the time you spend, because we do spend a lot of time working, after all.
Speaker 1:Yeah, you have eight plus hours every day and that's a big chunk of your life, so if you don't like it. That's too bad.
Speaker 2:And is there any other advice that you would like to give to someone who's starting out in the field, or you would like to give yourself? If you could talk to yourself when you were first starting out.
Speaker 1:Okay, that's a good question. I will say stay open-minded and curious. And that probably reflected on when I say pay attention to small things that doesn't check out in your experiment, and open-minded it's not. And curious those two. Sometimes, when people mention this too, maybe they were more referring to learning new things, things you don't know about, but I'm more thinking about the part that, since that you have opinion on. For example, you think this algorithm or this field or this topic is not promising, it's not good and it's not useful. Or you conclude something from your past experiment and you are very likely making that conclusion because you had enough data point and you did it in a logical way. But still be open-minded that you might be wrong because you are limited from what you see. Maybe you are very logical, but the fact you see maybe it's not a whole choice, you might not understand everything. So when people have an opposite opinion than you, I would say try your best. To this is also advice to myself. When you ask that question. I try to do this as much as possible. Maybe I probably want to do even better.
Speaker 1:Spend time, listen to people who disagree with you and not only be implied and just listen but understand why they have their opinion and then you can make a decision from there. Are you convinced? Or maybe most likely you don't, because there's a reason why you believe what you believe, and the researchers are usually pretty good, they're logical, they're good at thinking. So the opinion you have might be a solid and more reasonable opinion. But still listen to people who disagree and understand why they hold that opinion and decide if they can convince you and my experience most often they don't convince me.
Speaker 1:But it is those moments like one out of 10 times. There's one time that you are convinced and that is actually the moment you realize you have gained a lot of understanding of something. So it's a small chance that you realize, oh, I was wrong. But in those moments you really start to have another level of understanding what you were doing. So I would say it's almost always worth the time. Take some time, listen and understand why some people disagree with you. I think that I should do more and I think if someone asks me what's important, this is probably what I would say.
Speaker 2:That's great. Thank you so much, Fadima. You wanted to add something.
Speaker 3:I would say I like your advice saying to listen to people who disagree with you. As I said, they might be right. There's a small percentage of them that might be right, but sometimes in my frame, the question is slightly different way and maybe communicating is slightly different way and then we learn. As I said, we learn from that process in trying to communicate in a different way. So I love that advice. It's so true. Thank you for that.
Speaker 2:Yeah, and I think, as you mentioned also, like, okay, maybe you only become convinced one time out of 10, but the other nine times you're still have to refine your understanding. If you want to at least convince yourself of your initial belief, you need to make sure. So even then, it's valuable to exchange with other people of differing opinions. I guess the last question that we were curious about was the most important leadership lesson you've learned, and how has it proven valuable?
Speaker 1:This is an interesting one. Okay, so I'm not in a At the moment. I'm leading a very small team, but I'm not in this position for long, so I am owning a people manager for about two years now. I wouldn't say I learned a big lesson or something, but since I start to have this job, I was exposed to materials and courses that are for how to be a better manager, how to be a better leader, and all this. There are a lot of advices to teach you how to show that you respect other people and how you, I would say, create a better manager image.
Speaker 1:But what I start to realize is, in order to be a good leader I wouldn't say I am already, but I aim to be for the future the thing is, maybe we should have think a lot on how to show respect to other people and all this the real question to ask is do you actually respect them? Do you care? Do you want good things for them? Of course you want success for your team, you want success for the company, but if you don't genuinely care and just try to behave like you care, it's probably not a good starting point. So I try to ask myself whenever I approach a people problem or something I need to support other people, I think I try to tell myself or ask myself do I care? Do I genuinely care about them, their career and starting from there, it's probably a good idea, and that's also what I observed from good leaders that I get to see around me. The better ones are doing this, so I'm trying to do the same thing and I hope I will do good.
Speaker 2:That's great. I think that's an important point is, if you actually care about the people around you, I guess leadership becomes more natural as well. And that's a great challenge, because sometimes I guess you don't initially always care, but you have to find ways to get there. I don't know if that's been your experience.
Speaker 1:You can always care about someone. I think it's more when you add an actual moment, there's a crisis or there's something you need to quickly fix, and then you may be taken over by the goal that you need to achieve, and then you start to think a lot about the consequences If this does not get done or we don't achieve this, and then something will happen. So we need to quickly fix this, and then you might be carried away by that emotion or that urgency of trying to fix something, and then you start to care less about your people. You might fix that thing for a short term, but a long term I don't think it's good and you might have more problems in the future. So it's just not. I don't think that's a success. If you only fix one thing and then people around you are not happy or they are not getting the benefit of fixing that thing. I guess it's just a loss.
Speaker 2:Yeah, it's a difficult challenge. To make everything come together cohesively, yeah, Vivian. So what are your plans for the year? What are your hobbies, interests, anything you'd like to share with people about what you're looking forward to?
Speaker 1:Yeah, I mean I'm quite excited to see I do think we're at a point that, in terms of high speed optical transceivers, we're going to see some changes. How we design them, they will look different than what they traditionally look like. So I'm quite excited to see all the innovations coming together to make better communication systems. And, yeah, and I do hope, more younger people join us and who are excited about this field and want to make contributions.
Speaker 2:Thank you so much, and thank you, fatima, as well. It was a pleasure to do this, but, yes, with both of you.
Speaker 3:Thank you, thank you, thank you, cherie, thank you, vivian, that was great.