10 Dec 2002
The pick of this week's hottest patent applications, including a design for a silicon light-emitting device.
• Title: High-efficiency silicon light-emitting device and modulator
Applicant: Unisearch, Australia
International application number: WO 02/097894
Scientists from the University of New South Wales in Sydney are looking to marry the worlds of semiconductor optics and electronics with their silicon LED. Martin Green and colleagues developed devices emitting at 1.1-1.2 micron. A pyramidal surface texture increases the rate of photon emission and Green reckons that an efficiency of 5% is possible, and maybe even a silicon laser.
• Title: Apparatus and method for controlling the operating wavelength of a laser
Applicant: Altitun, Sweden
International application number: WO 02/097936
The tunable laser specialist owned by ADC has come up with a novel approach to locking the output wavelength of lasers used in telecoms applications. Instead of employing the normal planar etalon, Altitun proposes a design that uses either a curved etalon or a wedge-shaped component. According to the application, this offers advantages both by providing two degrees of freedom in alignment and reducing the cost and difficulty of assembly.
• Title: Short-wavelength zinc oxide light-emitting device and the manufacturing method thereof
Applicant: Young-Chang Kim, Republic of Korea
International application number: WO 02/097903
The LEDs comprise a layer of p-type indium phosphide (InP), which is formed by doping an InP substrate with zinc. A zinc oxide layer is then deposited on top, yielding a semiconductor device emitting in the ultraviolet region.
• Title: 3D display using micromirrors array
Applicant: University of Cincinnati, US
International application number: WO 02/098145
This invention incorporates a collection lens that gathers, directs and enlarges three-dimensional light images reflected from an array of interleaved plastic micromirrors.
Michael Hatcher is technology editor of Opto and Laser Europe magazine.