The 7 Habits of Highly Effective Optical Innovation
By Paul Momtahan
Director, Solutions Marketing
Optical innovation has a key role to play as the world needs ever more bandwidth, with effects of the COVID-19 pandemic only increasing demand. Innovative optical solutions provide network operators with more bandwidth at a lower cost per bit that can be transmitted over longer distances, ultimately enabling them to offer more services at lower prices and to be more competitive. It also has a key role to play in reducing the power consumption and CO2 emissions that are the internet’s dirty secret.
In 1989 Stephen Covey wrote his bestselling book, “The 7 Habits of Highly Effective People.” What does a 30+ year old business and self-help book have to do with optical innovation? Well, just as Mr. Covey outlined seven habits of highly effective people, at Infinera we have identified seven “habits” of highly effective optical innovation companies – or perhaps better stated, seven key disciplines that are necessary to create truly innovative and disruptive optical transmission solutions.
Figure 1: The seven optical innovation disciplines of the Infinera OIC
- ASIC/DSP Design
The digital ASIC/DSP plays a critical role in coherent transceivers. In addition to coherent signal processing, including impairment compensation, it is responsible for analog-to-digital and digital-to-analog conversion, forward error correction (FEC), performance monitoring, and encryption. Advanced functions such as Nyquist subcarriers, probabilistic constellation shaping (PCS), soft-decision forward error correction (SD-FEC) gain sharing, and dynamic bandwidth allocation (DBA) are all performed in the ASIC/DSP. Infinera’s ASIC/DSP design team, part of our Optical Innovation Center (OIC), has been responsible for multiple generations of ASIC/DSP, including the third-generation 500 Gb/s engine, fourth-generation Infinite Capacity Engine (ICE4), and sixth-generation Infinite Capacity Engine (ICE6).
- PIC Design
Infinera pioneered photonic integration with the industry’s first large-scale PIC in 2005 and continues to lead the industry with its sixth-generation PIC in ICE6. Leveraging high-performance indium phosphide, Infinera’s PICs integrate a wide range of optical functions on a single chip. This reduces cost, footprint, and power consumption while improving performance and reliability.
- PIC Manufacturing
Infinera has invested heavily to build its own state-of-the-art indium phosphide PIC fab and is the only equipment manufacturer to have done so. In addition to the obvious cost advantages of vertical integration, it enables fast redesign to optimize performance as well as tight quality control and a faster ramp to volume for new technologies and components such as ICE6.
- Analog Electronics Design
In addition to the DSP and PIC, coherent transceivers also require high-performance analog electronics. These include drivers that convert the low voltages from the ASIC/DSP to the higher voltages required by the modulators, as well as transimpedance amplifiers that convert current from the photodetectors to the voltages required by the ASIC/DSP. In-house design of the critical analog ASICs is an additional core discipline of the OIC.
- Advanced Packaging
Packaging plays an important role in high-performance optical engines, and it can be even more important in cost- and footprint-sensitive compact pluggable coherent transceivers such as XR optics. An additional area of OIC expertise is the packaging of coherent transceivers leveraging the latest materials, design methodologies, and manufacturing techniques.
- RF Interconnect Design
Coherent optical engines include electrical/radio frequency (RF) interconnects between the ASIC/DSP and analog electronics, and between the analog electronics and the photonics/PIC. These RF interconnects are critical to the performance of the optical engine, especially at ultra-high baud rates.
- Holistic Co-design
With all the elements of Infinera’s optical engines, including the ASIC/DSP, PIC, analog electronics, and packaging, designed in-house, holistic co-design allows the optimization of any trade-offs in order to maximize performance.
Figure 2: Key OIC innovations and products
A relentless focus on these seven disciplines has enabled the world-class team of scientists and engineers in the Infinera OIC to take multiple optical component innovations from vision to network disruption. Industry firsts include the first large-scale PIC and the first coherent PIC. Additional OIC innovations, many unique, include the following:
- Infinera’s unique SD-FEC gain sharing enables the errors of a more challenged wavelength to be shared with a less challenged wavelength to equalize the FEC gain, thus maximizing the capacity of the more challenged wavelength.
- Nyquist subcarriers, another Infinera first, can significantly reduce sensitivity to nonlinearities and the effects of chromatic dispersion, and contributed to the multiple subsea spectral efficiency records set by ICE4.
- Ultra-high baud rates, 96 Gbaud with ICE6, enable a step-change increase in wavelength capacity-reach, and recently helped ICE6 achieve a record-smashing 800G reach of 950 km in a live network trial.
- Infinera’s unique long-codeword PCS implementation brings PCS gain close to its theoretical maximum.
- Infinera’s unique DBA brings Nyquist subcarriers and LC-PCS together in order to maximize capacity-reach.
- XR optics, the world’s first and only point-to-multipoint point coherent solution, breaks the point-to-point shackles of conventional optics, enabling radically lower aggregation network total cost of ownership.