Why @UCBerkeley and @MIT Optical Processor means Li-Fi and 5G Wireless by 2020

“This is a milestone. It’s the first Processor that can use light to communicate with the external world. No other Processor has the photonic I/O in the chip.”

Associate professor of electrical engineering and computer sciences at the University of California, Berkeley Vladimir Stojanovic, commenting on the development of a working Optical Processor.

Optical Processors may soon be possible within my lifetime.

A collaboration between UC Berkeley and MIT (Massachusetts Institute of Technology) has yielded a process that uses Optical pulses instead of electricity as reported in the article “This futuristic chip transmits data in an entirely new way”, published December 25, 2015 By Gabe Carey, Digitaltrends.

This Processor, which consists of 70 million transistors and 850 photonic components onto a 3-by-6-millimeter chip, isn't all Optical, as it still has to be powered by electricity as noted in their publication in the Thursday December 24^th 2015 print issue of the journal Nature!

The main researchers on this project are all quite noteworthy:

1.      Mark Wade, Ph.D. student at the University of Colorado, Boulder

2.      Yunsup Lee, a Ph.D. candidate at UC Berkeley

3.      Jason Orcutt, an MIT graduate at IBM Research Center in New York

In their experiments, the researchers transmitted data to a receiver 10 meters in a fiber optic loop as a test of its data transmission capabilities.

This makes this Optical Processor more suited to be used in Switches and routers rather than in Smartphone, tablets and computers to quote Associate professor of electrical engineering and computer sciences at the University of California, Berkeley Vladimir Stojanovic: “Light-based integrated circuits could lead to radical changes in computing and network chip architecture in applications ranging from smartphones to supercomputers to large data centers. Something computer architects have already begun work on in anticipation of the arrival of this technology”.

UC Berkeley and MIT Optical Processor – Telecom Providers rejoice, consumer products coming

It’s a huge breakthrough, as the data inputs into the Processor are all Optical and its made in a  foundry that mass-produces high-performance computer chips as declared in the Press Release entitled “Engineers demo first Processor that uses light for ultrafast communications”, published DECEMBER 23, 2015 By Sarah Yang, Berkeley News.

They fabricated the microprocessor in a foundry that mass-produces high-performance computer chips, proving that their design can be easily and quickly scaled up for commercial production. 

This is quite fortuitous and is similar to what I'd envisioned when IBM had developed a Photonic Optical Processor as described in my blog article entitled “IBM develops 25Gbps Photonic Optical Processor at the 90nm level - IBM's Red Dawn for Optical Processors”. 

However it may only find application initially in Router and Servers used in Telecom Switches.

So what does those this mean for Computer, Smartphone and Tablet Processors in the Future?

UC Berkeley and MIT Optical Processor – How the Optical Processor was made

Commercial production is around the corner, possibly by 2020 as 5G is coming as reported in my blog article entitled “ITU publishes 5G IMT-2020 Roadmap - Why US Telecom Providers, @Digicel_Jamaica and @LIMEJamaica like to travel off the beaten Path”. 

The researchers deigned the Optical Processor to communicate in light only. So no Optical to electrical conversion was done with the chip. This means that the motherboard or chipset was fiber optic. 

The researchers developed photonic I/O components to guide the UV light through the Processor:

1.      Silicon waveguide

2.      Ring modulator

3.      Photodetector

4.      Vertical grating coupler  

The entire chip was fabricated using conventional process found in a typical foundry that mass-produces high-performance computer chips. This makes adjustments and optimization possible without any radical changes to the fundamental process already being used to fabricate Processors.

First, they made a few changes to the p and n type doping needed to make the transistors as well as the etching masks so as to create the necessary Optical waveguide traces within the silicon.

Once that problem was cleared, they then had to develop an interface within the Processor between the Optical input from the outside world, within the silicon waveguide and the electrical parts of the Processor. They designed a Vertical grating coupler that performed this task.

The researchers took advantage of the fact that using the silicon doped with germanium acts as a photodetector. Thus they used this unique property of germanium to make a photodetector to read the UV Data pulses travelling along the silicon Waveguide.

Transmission was done via the use of the ring modulator which provided a low-energy modulation of the UV light. This ring modulator had a p-n doped junction connected to the silicon waveguide and effectively was a mini LED (Light emitting Diode) that produced UV to send data along the waveguide to the outside world.

Most likely as the UV light leaves the Optical Processor via the vertical grating coupler, an amplifier amplifies the light to be interpreted by the DSP (Digital Signal Processor) as in a mobile device or Fiber optic modem as in a desktop computer or router.

Ph.D. candidate at CU-Boulder and a co-lead author of the study Mark Wade is confident of this, quote: “We figured out how to reuse the same materials and processing steps that comprise the electrical circuits to build high-performance Optical devices in the same chip. This allows us to design complex electronic-photonic systems that can solve the communication bottleneck in computing”.

UC Berkeley and MIT Optical Processor – Cool Operator that runs faster

This Optical Processor demonstrates that faster Processors don't need to have more power, as is the case with silicon Processors. The Optical Processor used 1.3 picojoules per bit, or roughly 1.3 watts of power for every terabit of data per second!

By reducing the need to power a large motherboard and a Processor as well as to convert data from Optical to electrics from the DSP (Digital Signal Processor) in the case of a smartphone or the Fiber Optic Modem in the case of a computer can make a computing device appear to be faster at lower power levels.

This makes the Optical Processor suitable for Routers and Switches for long haul Fiber Optic Networks as they’ll process data without the need for Optical-electrical conversion as noted in “Chip promises faster computing with light, not electrical wires”, published December 23, 2015 by Stephen Shankland, CNET News.

It also makes the device run cooler, making it possible to reach faster speeds without having to increase cooling requirements.

UC Berkeley and MIT Optical Processor - Optical Bandwidth just in time for 5G in 2020

This Optical Processor has benefits in terms of bandwidth, as the data input and output is Optical, allowing the dual-core design to process more data.

According to the researchers, it can process some 300 gigabits per second per square millimeter, about 10 to 50 times greater than its electronic counterparts!

The fact that it directly processes Optical Data means that the Developement of Li-Fi Networks can progress unhindered by limitations of the Devices as noted in my blog article entitled “Why pureLiFi Solar Powered Li-Fi is coming to Apple iPhone with 5G Internet by 2020”.

This development will be bang on time as 5G is expected in 2020. Expect similar tech to be licensed and used in smartphones, Tablets, Smart TV as well as desktop computers by 2020.