How will 200G (and beyond) per Lambda IM/DD Compete with Coherent Technology?


Frank Chang, Source Photonics, USA
Hai-Feng Liu, HG Genuine, China
Sam Palermo, Texas A&M Univ., USA
Mitsuru Takenaka, Univ. of Tokyo, Japan


How will 200G (and beyond) per Lambda IM/DD Compete with Coherent Technology for Intra-DC Applications?

Ethernet speeds continue to climb up to serve the bandwidth needs by hyperscale data centers. Today, IM/DD has been extensively used in intra-data center interconnects for its lower cost/power and simplicity while coherent technology has been widely used in metro data center interconnects for its higher capacity/l and capability to compensate various link impairments. With the recent advances in DSP and photonic integration, the complexity and power consumption of coherent systems have been decreasing rapidly. As the data rate moves from 100G/l to 200G/l and beyond, the question arises as to whether IM/DD can continue to scale or migration of coherent technology into intra-data center networks is inevitable. 

This WS aims to stimulate debates on IM/DD vs. coherent detection for intra data center applications. Topics will include but not limited to:   

  • What are the viable 200G/l IM/DD technologies including approaches and modulation schemes, taking ADC/DAC, DSP, FEC, etc. into account?
  • Is higher spectral efficiency offered by coherent technology worth the extra complexity?
  • How to tailor the complexity of coherent electronics to be more competitive in terms of cost, power and latency?  
  • Are there foreseeable feasible technologies for beyond 200G/l?
  • What will be the application boundaries between IM/DD and coherent to achieve reach objectives required?  
  • What are the aspects and key trade-offs of using coherent for intra data centers?
  • Is it just simpler and better to make use of more wavelengths and more fibers?

This WS will solicit experts from data center operators, system and module vendors, and IC suppliers to share their views on those debatable issues. Interaction b/w speakers and audience through Q&A is highly encouraged.


To be determined.