Integrated photonic systems are expected to drive the development of new applications, including Ultra HD broadcast

4 min read

Photonics is turning out to be big business – and the technology holds the prospect of being even more important in the future. A market that was valued at something like $350billion in 2005 has grown to be worth around $1trillion in 2015, driven by the increasing use of displays. Not bad for a technology that only saw the light of day in the early 1960s.

Tim Stokes, managing director of Hamamatsu Photonics UK, told a recent seminar: "In 10 years, photonics will become more important to the UK's economy than the pharmaceutical industry is today." He said the global photonics components market is currently worth €100billion a year, with 2750 companies operating in 46 countries. "In the UK," he continued, "there are more than 1000 photonics related companies employing some 70,000 people. Photonics is estimated to contribute more than £10billion a year to the UK economy; a figure which is growing by at least 6% a year."

Further confirmation of the importance of photonics in the future came in October 2014, with the announcement by the US government that it is to invest more than $100million to set up a manufacturing institute dedicated to the development of integrated photonics technologies.

According to a White House statement: "The Integrated Photonics Manufacturing Institute - with more than $200m in public and private resources – is expected to comprise the largest federal investment to date, reflecting the complexity of this technology, its importance to national security, and its revolutionary potential."

Stokes also pointed to Europe's focus on photonics, noting that it is one of five Key Enabling Technologies identified by the European Commission. According to the EC, Europe needs to better exploit the innovation capacity of the more than 5000 existing photonics SMEs and the innovation leverage potential of the more than 40 existing innovation clusters and national platforms. Areas to be supported, the EC suggests, include: optical communication for data centres; high throughput laser based manufacturing; and photonics IC technology.

Photonics can be defined as the generation, transmission and detection of light, with a bit of processing thrown in. Applications span from lasers to long distance telecommunications and displays to the emerging areas of silicon photonics and LED lighting.

So it's no surprise to find that research into photonics is being undertaken in a number of UK universities. While some of that work is addressing the fundamentals of photonics, others are looking at the topic more broadly.

One such centre is the UCL-Cambridge Centre for Doctoral Training in Integrated Photonic and Electronic Systems (IPES). According to the Centre, the technology is moving from the creation of photonic devices in isolation towards their assembly into systems and an approach where photonic functions are integrated with electronics, software and applications. As a result, it says, there is a need for a new type of researcher equipped with a clear understanding of photonic and electronic systems, applications drivers for the technologies and the business tools used to determine the adoption of new technological solutions.

The Centre was founded in 2009 as the Centre for Doctoral Training in Photonic Systems Development. In 2013, funding for a further eight years was obtained from EPSRC, allowing a stronger focus on the integration of electronic and photonic systems.

Leading the Centre's work is Professor Alwyn Seeds, head of the Department of Electronic and Electrical Engineering at UCL. He explained more about the Centre's operations at a recent industry day held in Cambridge. "The objective of the Centre is to train researchers in a particular way so they can work with systems involving electronics and photonics. We want students to have enough expertise to make the right research decisions when it comes to developing new products and services."

The Centre offers a four year programme in Integrated Photonic and Electronic Systems, which combines a one year Master of Research (MRes), followed by a three year doctorate (PhD). The MRes course is designed to provide students with the time needed to absorb the context of photonics research and to learn tools and methods that can support their research. Students then register for a PhD, working on a project defined partly by industry input.

"In their first year," said Prof Seeds, "they are trained in things outside what they know already, but which are essential. For example, an electronic engineer needs to know what a quantum transition is and how to make use of it."

While the main aim of the seminar was to highlight work being undertaken by post graduates, there was also some insight into how photonics is being developed as an enabling technology by UK companies.

Nick Parsons, chief technology officer of Polatis, described his company's technology, saying its products were targeted at software defined networks, as well as sensor networks in the oil and gas sector.

Polatis has been involved in a range of European photonics projects, including DISCUS, COSIGN and C3PO. It has developed what it calls DirectLight, pictured, an optical beam steering technology which has the ability to support point to point connections between arrays of fibres.

The approach uses piezoelectric actuators to align collimated beams of light from arrays of input and output fibres, with alignment maintained using feedback from integrated position sensors.

David Smith, CTO of Huawei subsidiary CIP Technologies, described work on the development of indium phosphide chips. He said drivers for the technology include greater spectral density and greater spatial density. "Our challenges are complexity, size and power," he noted, "but the solution will come from photonic integration."

Following the European theme, Hamamatsu's Stokes pointed to the establishment by the company of a European Innovation Centre in Switzerland, headed by Professor Peter Seitz.

Hamamatsu is developing optical devices with even more sophisticated functions and higher performance by using micro opto-electro-mechanical systems – or MOEMS – technology. The technology merges MEMS devices with micro optics in order to sense or manipulate optical signals using such elements as optical switches, optical cross connects and tunable lasers.

Research presentations were given by UCL's Adam Funnell, who is working with BBC R&D to develop dynamic photonic spanning networks for smart Ultra HD production services, and Laurent Michaux from the Cambridge Institute for Manufacturing, who described his work on laser induced shock wave processing of metallic coatings.

Funnell, presenting alongside Chris Chambers – principal infrastructure engineer with BBC R&D – outlined the challenges facing broadcasters as they begin to think about how to implement Ultra HD technology.

Top of the list of challenges is the amount of data which needs to be handled. To get the benefits of Ultra HD, images need to be captured at 100frame/s or more and with more bit/pixel for greater colour depth – this translates to 24Gbit/s. Another challenge is the studio and the gallery might not be in the same place, so there are latency issues – if something happens in front of a commentator and the director wants a different view, the action may be over before the change is made.

Ultra HD broadcasting, Funnell concluded, needs flexibility, compatibility, low complexity, low latency and low power. And the BBC is looking to photonics to solve some, if not all, of the problems.