Is the Future Finally Here? What a GaAs!

Back in 1983 I was working for Texas Instruments during the beginning of the push to let common electrical engineers develop their own CMOS application specific ICs (ASICs). This would eventually the be the fuel that fed the semiconductor engine to reach over $335 billion in 2015. At that time, I was a young guy and I had a rascally old boss who used to say, “Gallium Arsenide – has been and always will be the technology of the future!”. Fast forward to 2016 and we witness the announcement byPOET Technologies Inc. that it has signed a definitive agreement to acquire all the shares of DenseLight Semiconductors Pte. Ltd. DenseLight is a Singapore-based privately held photonics company that designs, manufactures, and markets photonic optical light source products to the communications, medical, instrumentation, industrial, defense, and security industries. These products are based on DenseLight processes using Indium Phosphide (InP) and you guessed it, Gallium Arsenide (GaAs). Have we met the future and is it “now”?

POET Technologies’ name is in fact an acronym for Planar Opto-Electronic Technology and they are working on moving from the lab into fab technologies for monolithically integrated opto-electronics or what POET calls smart optical components. Much of their value proposition is based on an invention they call DOES (Digital Opto-electronic Switch). This switch is used in their proposed products, that would replace with one POET IC, an existing transceiver made up of a hybrid assembly of a VCSEL (vertical cavity surface emitting laser), laser driving electronics, a GaAs photo detector, and a receiver IC consisting of a TIA, limiting amplifiers and an output amplifier . The existing transceivers have been effective operating at 10Gbps to 25Gbps over multi-mode fiber (MMF) up to about 100 meters. However, POET claims that these solutions fail for 500 meter links, especially at the 25Gbps link rates. This has prompted the market to look to multi-die solutions that use a combination of a silicon photonics IC (PIC), an electronics IC (EIC) and a laser along with single mode fiber (SMF) for the reaches past 100 meters.

POET believes that they can use their III-V (GaAs) VCSEL epitaxy process and their new DOES technology to integrate both VCSELs and electronic FETs (field effect transistors) and HBTs (Heterojunction Bipolar Junction Transistors) on a one-chip solution that will provide 10X improvement over what can be provided by silicon photonics in this space (see POET white paper here).

POET started life as OPEL Technologies out of Toronto, Canada selling III-V semiconductor devices through a U.S. company named ODIS Inc. to the military, industrial and commercial market spaces. They specializing in infrared sensor arrays and ultra-low power random access memory. They changed their name to POET Technologies in June of 2013 and have been working ever since to use their expertise in III-V processes to become a premier supplier of opto-electronics processes and smart optical solutions. Over the last year POET has made some major strides to bring their technology out of the lab and into the fab. A short time line follows:

• August, 2015: POET announced a manufacturing services agreement with ANADIGICS, a New Jersey company, to prove out their new hybrid VCSELs in ANADIGICS 6-inch fabrication line.
• September, 2015: POET reported they were expecting prototypes of their VCSEL products in Q2 of 2016, with hopes of providing a 10X improvement in energy consumption, component cost and form factors used for data center short reach and very short reach communications.
• January, 2016: POET made separate announcements of a supplier agreement with EpiWorks, a wafer manufacturer specializing in epitaxial growth and a manufacturing services agreement with Wavetek Microelectronics Corporation, that specializes as a GaAs foundry.
• March, 2016: POET announced a R&D initiative with IMRE/A*STAR in Singapore to develop smart pixel technology for the Augmented Reality market using GaAs and Gallium Nitride (GaN).
• April, 2016: POET announces acquisition of all shares of DenseLight, whose fabs in Singapore specialize in Indium Phosphide (InP) and GaAs. Also in April, POET announced that they had multiple wafer lots of their hybrid VCSEL technology produced as promised in Q2 of 2016 and were in the process of characterizing them. They also announced they are working on a new GaAs-based resonance cavity based photonic sensor targeting prototypes by the end of 2016.

All of that said, I’m not quite sure the future is here yet. Prototypes are interesting but the proof is in real production volume products. It appears however that POET is getting closer and showing good progress. For the sake of integrated photonics, whether it be Si or GaAs based, I hope they are successful. It would mark a major milestone towards the commercialization of integrated photonics out of the labs.