FEATURED TECHNOLOGY: SPONSORED CONTENT


performance and power consumption, thanks to the avoidance of coupling losses. ‘One of the big differences between InP


and silicon photonics,’ said Momtahan ’is how they use different physical effects to change the refractive index. InP uses the opto-electric effect and silicon photonics uses the plasma- dispersion effect. Te indium phosphide effect is much more efficient.’ Momtahan explained there are two things


we can look at in terms of efficiency. ‘One,’ he said, ‘is how long the modulator is, and the other is how much voltage. Comparing InP with silicon photonics to get the same effect, we either need 10 times the length of modulator or 10 times the voltage. So, InP is 10 times more efficient at changing the refractive index.’ Tis, he added, will have a fundamental


physical advantage in terms of the modulator. ’Generally, when you go to a new speed, a higher baud rate, it is typically InP that is the first material to provide the modulator for that. But both technologies are improving. Eventually silicon photonics will probably do 90+ GBd modulators, but at that stage InP will have moved on to 120+ GBd.’


Need for speed Momtahan believes these speeds are the way in which the industry will move in terms of PICs. ‘Te industry is looking at 120GBd as a next step. InP will be a key component of that in terms of the photonics, because of the aforementioned benefits. What you will see


is the next generation of modulators that come aſter the current 90+ GBd. Tese will also be InP.’ As well as the provision of instant bandwidth,


the benefits of any coherent technology cannot be discussed without mentioning distance. Tis is another area in which Momtahan believes there is a distinct advantage. Te firm partnered last year with network


provider Windstream for a live network trial that successfully achieved 800Gb/s single- wavelength transmission over 730km across Windstream’s long-haul network between San Diego and Phoenix, using Infinera’s Ice6 giſt-generation coherent technology. Another successful test was performed alongside th operator Verizon, which achieved an 800Gb/s single-wavelength transmission over 667km between Nashville and Atlanta; and a 600Gb/s single-wavelength transmission over 2,283km from Atlanta to Memphis, with a loopback in Memphis. ‘It is advantageous to the industry being able


to do these very-high-capacity wavelengths of long distances, that we’re doing with Ice6,’ explained Momtahan. ‘Tat also has significant benefits, in terms of driving down the cost-per- bit, driving down the power consumption, and increasing the spectral efficiency. So that’s kind of where we’re at with the Ice6.’


High-performance Momtahan believes that InP could be the superior photonic integration material for the high-performance segment, although he recognises that silicon photonics can still be an


EVENTUALLY SILICON PHOTONICS WILL


PROBABLY DO 90+ GBD MODULATORS, BUT AT THAT STAGE INP WILL HAVE MOVED ON TO 120+ GBD


atractive option for applications that perhaps have more modest data rate requirements, or where vendors may not have the necessary expertise to build a fully-integrated InP-based PIC, or are unable to make the substantial investment in building their own InP manufacturing facility. Several research groups suggest one


promising path could be hybrid integration, integrating lasers on top of complex silicon photonics with the integration of silicon photonics PICs with InP PIC circuits. ‘Time will tell,’ said Momtahan. ‘Tere’s a litle bit of a batle going on there. Te silicon photonics folks are trying to catch up. We’ll see what happens. Certainly for Infinera, our future generations will be based on InP.’ n


NEW WHITE PAPER


VIEW FOR FREE*


THE ADVANTAGES OF INDIUM PHOSPHIDE PHOTONIC INTEGRATION IN HIGH PERFORMANCE COHERENT OPTICS


This paper first examines the inner workings of a high-performance transceiver to identify the optical functions that are needed and the benefits of integrating these functions into photonic integrated circuits (PICs). It then looks at the material options for each function, comparing indium phosphide (InP) and silicon photonics (SiPh).


AVAILABLE ONLINE NOW WWW.FIBRE-SYSTEMS.COM/WHITE-PAPER www.fibre-systems.com @fibresystemsmag *Registration required


Issue 30 n Winter 2021 n FiBRE SYSTEMS


13


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38