Updated: February 17th, 2020

A gap between the current electronic integration industry and photonic integrated circuit (PIC) technology is present under the subtle tension between “introductory delay” and “collapsing to zero.” Recent standards movement reveals the evidence of this trend through extra-short reach (XSR) definition and points to printed optical board (POB) as the most probable next enabling technology for this ecosystem.

By Kihong (Joshua) Kim and Jeremy Buan, Hirose Electric, Inc. photonic

Photonics has been recognized as a next-generation interconnect solution for electrical systems for many years. However, projected milestones, such as product releases, have been subject to introductory delays. There are two main causes for these delays.

Electrical serializer-deserializer (SerDes) interfaces have led to revolutionary technologies that have extended the use of copper media. However, these developments always drag the photonics debut back to some extent, which we call introductory delay. As an example, SerDes technology is able to compensate for intrinsic material problems, such as dielectric dissipation induced loss, or dissipation factor (Df), and reflection noise through signal conditioners, such as continuous time linear equalizers (CTLE), feed-forward equalizers (FFE), and decision-feedback equalizers (DFE). Other factors, such as mechanical design innovations, also lead to delays. For example, far-end crosstalk (FEXT) is a major cause of suppressed data rates.