Southampton Photonics (SPI) seems to have demonstrated several levels of resourcefulness through the tough times and is claiming to have actually doubled its turnover between the most recent two quarters of trading. The company has also made two key announcements in as many months that suggest enduring buoyancy in its core business of speciality fibre-based solutions (see Product Focus: Fibre, p. 13). With a 610-W output, the company has developed its highest ever power from a fibre laser, and it has launched a range of fibre-laser "building blocks."
Called the redPower fibre-laser family, these blocks are a series of modulatable continuous wave (CW) products delivering up to 30 W, a short-pulsed product family with peak powers starting at 25 kW and energies in excess of 1 mJ, and a 100-W modulatable CW unit. SPI believes its redPower series offers the highest short-pulse energy available from a fibre laser. The CW products are based around GTWave technology. GTWave fibre offers efficient, high-absorption cladding pumping while providing a scalable, simple, reliable, volume-based architecture. The redPower products contain SPI's fibre Bragg grating technology that allows ultra-fine optimisation of the laser cavity.
Having just returned from Munich's Laser 2003 and its new little sister show Fibercom, SPI chief executive David Parker told Lightwave Europe, "Although Fibercom itself was relatively quiet, there was a lot of interest at the Laser show across SPI's portfolio." Never solely reliant on the telecommunications sector, the company identifies four distinct markets for its products: communications, industry, aerospace, and analytical, which includes medical, therapeutic, and diagnostic applications. "For SPI, there is growth in all three of the nontelecoms sectors, and not only for the replacement market," adds Parker. "The optical 'coms' industry will continue to struggle for some time, but we are investing and continuing to expand. Our telecoms customers understand that we are still open for business.
"Having achieved at 610 W the record output from a fibre laser, we are now presenting finished products ranging from 10 to 100 W. We are working toward a 1-kW laser as a building block; this would be a standard unit of power. So far, kilowatt fibre lasers have suffered from poor beam quality. It's unlikely that the communications industry will need this high power, but it could be useful in semiconductor processing and manufacturing."
One sign that SPI has some confidence that the fibre optics development industries could see some improvement in relation to the telecoms industries is that SPI has brought out an L-band-capable fibre laser, which Parker says would be for "recovery-based" deployment. "We are starting to see some increase in the level of enquiries or the odd deployment where somebody wants to put in three extra channels, but we don't see much evidence of large scale deployment," admits Parker.
"Industry is rapidly recognising the benefits offered by fibre lasers," notes SPI business development director Stuart Woods, "and our technology is not only expanding the traditional laser applications space, but also opening up new application areas." Woods says the 610-W fibre laser—achieved with a single fibre gain module—demonstrated that cladding-pumped fibre lasers can produce the high powers needed to compete with more traditional [semiconductor] laser technology in applications such as remote welding by offering high powers which preserve beam quality.
The SPI team led by Johan Nilsson produced over 600-W output power at 1090 nm from an ytterbium-doped fibre laser. According to SPI's roadmap, single-fibre singlemode output powers well in excess of a kilowatt will be achieved in the not too distant future. These lasers could then be combined to produce multi-kilowatt solutions with excellent beam quality, efficiency, and reliability. The work so far has been funded by the U.S. Defense Advanced Research Projects Agency under its high-power fibre-laser program.