The eponymous Zepler Institute continues the work of an industry pioneer

Yet, compared with many areas of science, electronics is a relatively new discipline: one of the world's first university electronics departments was established less than 70 years ago at Southampton. It was founded by Eric Zepler, who fled Nazi Germany for Britain in 1935. Zepler's pioneering role in electronics has recently been celebrated by Southampton University, which founded in September 2013 the Zepler Institute, the UK's largest photonics and electronics institute. The institute is a multidisciplinary research centre that combines expertise in photonics (where light meets electronics), advanced materials, quantum technologies and nanoscience. Much of that work would be virtually unrecognisable to Zepler, such has been the progress in electronics since he died in 1980. But he made an outstanding and pioneering contribution to radio receiver development, as well as to the teaching of electronics. He first worked in Britain for the Marconi Wireless Telegraph Company, and his designs of radio receivers and transmitters were used by Bomber Command during World War II. In 1947, he founded the Department of Electronics at Southampton and developed the Southampton Postgraduate Diploma in Electronics, which became renowned as the outstanding qualification for professional electronics engineers in the UK. Zepler also helped to establish electronics as a clearly separate discipline from electrical engineering. As a member of the Institution of Electronic and Radio Engineers, he helped to formulate its educational policies and became its president in 1959/60. Since Zepler, Southampton University has been a leading research centre in electronics and photonics, especially in the development of the physical hardware of fibre optic technology that laid the foundations for much of today's worldwide telecommunications network and hence the Internet. This is still a core interest, notably in ultra high bandwidth communication technologies. Other innovative areas of study include biophotonics for point of care diagnostics, phase change memory, sensors for harsh environments and fundamental research into quantum devices and high power fibre lasers. The Zepler Institute is led by Professor Sir David Payne, who is also director of the University's renowned Optoelectronics Research Centre (ORC). Prof Payne's position is particularly appropriate at an institute where high bandwidth communications is core, because it was his contributions to optical fibre technology and invention of erbium doped fibre amplifiers that created the basic platform for today's global high speed internet. Prof Payne's pioneering work in fibre technology in the 1970s resulted in most of the special fibre based systems used today. He also led the team that developed the single mode silica fibre laser and broke the kilowatt barrier for output power. Some of the highest power fibre lasers in the world have been designed by Prof Payne and his team. It is not just the Internet that has benefited. Fibres developed at Southampton have been used in some highly prestigious projects, where the most critical levels of performance are required, like NASA's Moon Rover and Mars Explorer, for example, as well as a raft of others, including many airliners and vital, life saving medical devices. The institute he now heads comprises more than 300 researchers, has £55million of secured research funding and more than 100 laboratories, making it the largest of its kind in the UK. One of its main facilities is a £120m, 2000m^2 state of the art cleanroom facility. While the backbone of the cleanroom is a world class fibre manufacturing plant, there is also an advanced silicon lithography facility, featuring a mixture of photolithography techniques to address pattern resolutions of down to 0.5µm, and electron beam lithography for smaller feature sizes. The photolithography equipment offers a combination of automatic and manual operation, can handle silicon substrates up to 200mm and can perform top and bottom side alignment. Partnered equipment allows a facility for wafer to wafer precision aligning and bonding. An automated resist processing station, provides a full range of spun and sprayed resists conformal to 2d and 3d surfaces. Facilities are also available for alternative nanopatterning techniques available such as microcontact printing, hot embossing and nano imprint lithography. There is also the capacity for atomic layer deposition and nanowire processing. Atomic layer deposition (ALD) allows sub monolayer (less than 1nm) films to be deposited. ALD can only be used to produce very thin layers down to a few nanometres, but does so with remarkable uniformity. Another advanced facility is the Nanofab, which is used for the production of nanowires and nanotubes by bottom up, self assembly. Here, nanowire and nanotube growth is catalysed using metallic or semiconducting nanoparticles and a chemical vapour deposition process is used to grow the nanowires or tubes using a vapour-liquid-solid growth process. One use of the system is to grow carbon nanotubes and silicon, silicon-germanium and germanium nanowires using catalyst nanoparticles. Several innovative projects are well under way at the Zepler Institute, in particular the International Coherent Amplification Network (ICAN). This aims to develop a new generation of ultra high powered lasers for use in particle acceleration. Ultimately, the aim is to turn such lasers into a revolutionary tool that could create an entirely new era for particle physics, one reason why CERN, home of the Large Hadron Collider, is involved. Other potential applications include generation of X-rays and gamma rays. Currently, high intensity lasers face two major obstacles: repetition rates and efficiency. Today's most powerful high-intensity lasers operate at a rate of a few pulses per day, when for practical applications they need to work at around 10^4 times per second. Also, they are very inefficient, with typical efficiency being a fraction of a per cent. With applications demanding average powers ranging from 10kW to tens of megawatts, it is uneconomic to generate this much power with such poor efficiency. ICAN is an EU project run by a consortium that includes the Zepler as a major partner, as well as CERN and more than a dozen research organisations worldwide. ICAN's aim is to replace the conventional massive glass disk amplifier chains used in the world's largest lasers with a network of parallel fibre amplifiers and other telecommunication components, based on a radically novel architecture, hence the name Coherent Amplifying Network. A typical CAN laser for high energy physics will use 100,000 fibres, each carrying a small amount of laser energy. One advantage is that it will use established elements such as fibre lasers and other components. The fibre laser offers an excellent efficiency of more than 30%, thanks to laser diode pumping. It also provides a much larger surface cooling area and therefore makes a high repetition rate possible. The hardest challenge is expected to be that of phasing the lasers together to within a fraction of a wavelength of light. But this looks to have been solved, with a preliminary proof of concept suggesting 100,000 fibres can be controlled to provide a laser output powerful enough to accelerate electrons to energies of several GeV at a repetition rate of 10kHz, an improvement of at least 100,000 times over today's state of the art. "Existing huge laser experiments fire sometimes only four times a day," explains Prof Payne. "We are now talking about the possibility that you could take as many as 1m of these and combine them together to achieve what no other laser can do. So you have an additional parameter of using millions of lasers together, and this has made all the difference to the idea of 'wake field' acceleration for the next generation of CERN accelerators, for example." Wake field acceleration is named after the effect of a boat creating a wake in water – the laser pulse does the same to the plasma it is in, creating ultra high speed waves. Plasma accelerators have immense promise for creating affordable and compact accelerators for various applications apart from high energy physics, including many medical and industrial applications. Another potentially invaluable application for ICAN is that it could make it economical to produce large numbers of relativistic protons over millimetre lengths, as opposed to a few hundred metres. These could be used to transmute the waste products of nuclear reactors, which at present have half-lives of hundreds of thousands of years, into materials with much shorter lives, on the scale of tens of years, transforming the problem of nuclear waste management. ICAN technology could also find applications in areas of medicine such as proton therapy. A second major project for the Zepler is the EPSRC funded Photonics Hyperhighway, which Prof Payne says is taking a new look at possible fibre technologies first considered in the 1990s. "Our aim is to achieve a leap forward in the fabrication of new fibres and associated materials. We are interested in the development of new photonic fibres capable of delivering up to a 1000 fold improvement in overall performance for telecom applications, by seeking to simultaneously lower both the loss and the nonlinearity, while also extending the transmission bandwidth. We are investigating new glasses for transmission, such as fluorides and tellurites, which are capable of infra red transmission to 3µm and beyond." Hyperhighway is aiming to develop new fibre amplifiers that work across the entire wavelength window, and investigating wavelength bands around 2µm that have previously been seen as unconventional. Such applications are for the future, but the Zepler Institute (in combination with Southampton University's ORC) has already spawned more than 10 start up companies, all local to the area. One is SPI Lasers, a supplier of high power fibre lasers for use in manufacturing. Now employing more than 250 people, SPI's systems have a wide range of applications in macro and micro machining, for uses such as rapid prototyping, laser welding of plastics and fuel cells, and laser cutting and marking in many areas. Other start ups include: Perpetuum – an energy harvesting company that has developed an electromagnetic vibration harvesting micro generator that can deliver sufficient energy to power industrial wireless sensors. Perpetuum's technology is being used to monitor the condition of bearings in hundreds of UK and European trains. Its generators have been used by Shell to monitor the conditions of gas field equipment. Fianium – which makes ultrafast, high power laser systems covering wavelengths ranging from 240nm to 2500nm. They include picosecond and femtosecond lasers, with applications including medical therapy and ultrafast material processing. Covesion – makes wavelength conversion crystals that transform the colour of lasers, which are used in laser projectors. It recently signed a licensing deal for components to be used in pico laser projectors. The practical success of these companies has been especially pleasing to Prof Payne. "The work at Zepler and the university is not pursuing crazy new ideas and just publications, it actually assists local industry, creates jobs and wealth and keeps our hi-tech industry here in the UK supported, and that's one of the things I'm most proud of."