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In
brief: Prima Luci, Fujitsu, Bookham Prima Luci wins $2 million for photonic component development, a Japanese team fabricates an efficient quantum dot laser, Syscan thinks LED backlights for LCD displays have great potential, and Bookham changes corporate domicile to the US. Prima
Luci secures $2 million investment The company holds a patent for redirecting light pulses using all-photonic components. Earlier this year it increased its portfolio of products by adding an "all-photonic" dispersion compensator operating at rates of up to 160 Gb/s. The funding will allow Prima Luci to complete orders for engineering samples, claimed to cost up to 90% less than equivalent alternatives, that have been placed by "several" optical systems manufacturers. Japanese
team develops an energy-efficient laser The Japanese partnership hopes to put the new device to practical use by 2007, citing low manufacturing costs and high efficiencies as the main benefits of the technology. The device, containing ten layers of 10 nm-sized QDs, emits at 1.3 μm and can operate at speeds of up to 10 Gb/s. The operating temperature currently ranges from 20-70 °C, but the team hopes to extend this figure to 0-85 °C. Syscan
joins LED backlight bandwagon Commenting on the opportunity for LED backlights to replace cathode tubes, Syscan's CEO Darwin Hu said: "Of the 180 million TV sets to be sold worldwide this year only 5% will be of the flat-screen variety, leaving much room for growth." "With flat-panel-industry revenues expected to surpass $80 million world wide during 2005, the opportunity for new advanced technologies is substantial," added Syscan's senior VP of business development, David Clark. Intense
appoints two non-executive directors Robertson is currently chairman of the power semiconductor company Cambridge Semiconductor, and non-executive director of telecommunications component manufacturer Ibsen Photonic. Snowden, a part-time academic at Leeds University, is also joint CEO of the communication components and systems firm Filtronic. Blue
LED demand fizzles Unit prices fell by 15-20% in the third quarter of the year, claims the report. It adds that shipments of high-luminance LED chips from Epistar dropped from 83 million units in the second quarter to 50 million units in the third quarter. Formosa Epitaxy is reported to have seen flat sales during the period. Taiwanese manufacturers have continued to increase blue LED manufacturing capacity in recent months. Kano
introduces blue-laser-based storage The Blue-Wav storage unit incorporates Sony's "ProData" optical drive to give a capacity of 23.3 GB on a single-sided cartridge. The drive also features transfer rates of up to 11 MB/s. The unit, which is aimed at document and medical imaging among a number of other other applications, is retailing at $2750-$3000. Terrestrial
triple-junction array generates kilowatt solar power
Developed by a team comprising the NASA Glenn Research Center, Boeing and Texas-based Entech, the concentrator array outputs more than 200 Wm-2 at 600 V. This achievement promises to improve solar-power generation using high-voltage arrays in terrestrial and space applications. "This could enable direct drive of certain types of ion thrusters, and lower conversion losses to high-voltage microwave transmitters," claimed the US team in a paper presented to the Solar Power From Space conference held in Granada, Spain, last month. In the longer term the successful deployment could even represent one of the first steps toward a space-based energy source that is capable of beaming power down to Earth via a laser. It also demonstrates that future terrestrial concentrator arrays based on triple-junction (GaInP/GaAs/Ge) cells could achieve unprecedented performance at an affordable price. The solar concentrator array used 240 Spectrolab GaAs P/N solar cells. Two separate modules were employed, each of which had an aperture area of 3 m2. At an altitude of 3000 m, the Hawaii location was nearest the team could get to having a space-like solar spectrum without executing an actual launch. More short-wavelength radiation can reach cells at the mountain-top site than at sea-level. According to the team, the peak power output of one of the concentrator modules reached 670 W - almost twice the capability of a standard module based on silicon solar cells. The typical energy output of the array each day was quoted as 16 kWh. "The results of this experiment lay the foundations for future terrestrial concentrator arrays," claimed the team. "Using color-mixing lenses and triple-junction cells [could] achieve unprecedented performance and eventual cost-effectiveness in mass production." If the module were deployed in space, the 200 Wm-2 conversion figure would immediately increase by more than 50%. Improvements in array design that have already been identified - such as improved optics - ought to further increase power output. "For future systems with wider cells, edge bus-bars and interconnect tabs, power output will be at least 20% greater, not including anticipated cell-efficiency improvements," said the team. Entech president Mark O'Neill has set out a long-term plan to reduce the power-to-weight ratio of solar systems used in space applications. His target is to reach 1 kW kg-1 specific power in 20 years, which he says will require an advance in multijunction-cell efficiency to 45-50%. A 40% reduction in cell mass would also be needed, something that O'Neill suggests could be achieved either by reducing the thickness of the germanium substrates used currently in triple-junction cells, or by employing a silicon substrate. The work could become the first phase of an end-to-end power-beaming demonstration, which would incorporate either a microwave or a laser beam to direct the generated energy. The plan is to install a NASA-designed power converter at the Hawaiian site as soon as funds become available. Densen
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