CompoundTek creating silicon OCL-band tunable laser module

14 Apr 2022

Wavelength-adjustable laser module under development with unnamed “stealth mode product company”.

At last month’s Lux-Enterprise Singapore Co-packaged Photonics/ASICS & Heterogeneous Integration Workshop, CompoundTek, a global foundry services provider in emerging silicon photonics (SiPh) solutions, described what it calls “ground-breaking results” with its hybrid Silicon O C L-band wavelength-tunable laser module that an unnamed stealth-mode product company ran with CompoundTek.

Through the development of the hybrid silicon laser technology, CompoundTek’s team led by Chief Operating Officer, KS Ang and Principal Engineer, Dr. Brian Sia, together with key personnel from the stealth mode company, have achieved laser engines that operate simultaneously in the O-, C-, and L-wavebands.

The O (ordinary) band spans 1260–1360 nm; the C (conventional) band, 1530–1565 nm; and the L (long) band 1565-1625 nm. The new laser engines have a wavelength tuning range of 175 nm across the three wavebands, with an output power and side-mode suppression ratio as high as 40 mW and 50 dB, respectively, CompoundTek reported.

As a corollary to highly advanced silicon manufacturing, silicon photonics has emerged as one of the fastest growing technologies. However, due to the material properties of silicon, the realisation of laser sources has represented one of the final frontiers in the area. CompoundTek says that “lighting up silicon is a strategically imperative initiative that needs to be urgently addressed”.

The primary advantage of wavelength-tunable laser lies in its ability to reduce the complexity of optical systems; a single wavelength-tunable laser can replace an array of single-wavelength lasers, thereby, simplifying system architecture as well as lowering inventory cost.

Distributed feedback (DFB) laser arrays and microelectromechanical systems (MEMS) vertical cavity surface emitting lasers (VCSEL) have been shown to demonstrate wavelength-tuning functionality, but there are limitations in terms of DFB array coupler loss and mechanical instability, respectively.

Littman/Littrow-configured external cavity lasers (ECL) have also indicated wide operating wavelength range; however, the application-space of these class of lasers are limited by their bulk, as well as higher vulnerability to environmental vibrations.

‘Attractive proposition’

Ang commented, “The challenge is for the development of a solid state-based laser diode with compact footprint, good performance that can be manufactured in a scalable, high-yield, and low-cost process. CompoundTek’s silicon photonics platform poses an attractive proposition for the realisation of the technology.”

“While there are many ways to build a tunable laser, what sets CompoundTek’s technology apart is our ability to integrate with silicon photonics devices which offer low propagation loss and high integration densities. Kudos to Dr. Brian Sia and the team, we are indeed very proud of this latest achievement,” he added.