13 Jul 2004
The pick of this week's patent applications including a coating which simultaneously blocks ultraviolet and infrared light.
• Title: Optical coatings for ultraviolet and infrared reflection
Applicant: Pill-Hwan Jung, Korea
International application number: WO 2004/056564
Pill-Hwan Jung, an inventor from South Korea, claims to have come up with a layered structure that simultaneously blocks ultraviolet and infrared light while transmitting visible light. Jung's structure contains two or three layers of silver, two or three layers of indium tin oxide and between two and four dielectric oxide layers. The dielectric layers can be made from silicon dioxide, titanium dioxide, aluminium oxide, zirconium dioxide, yttrium oxide or tantalum pentoxide. Jung's patent application also discusses how this structure could be fabricated onto a glass or plastic substrate and used as a window.
• Title: Enhancing fiber-optic sensing technique using a dual core-fiber
Applicant: The Regents of the University of Michigan, US
International application number: WO 2004/057386
Inventors in the US are trying to patent a dual core optical fiber which they say is ideal for use in fiber-optic sensing experiments. According to the inventors, a second smaller core sits coaxially within a larger core, which in turn is surrounded by an outer cladding layer. The smaller core delivers laser pulses to a test sample. "This takes advantage of the merits of both single and multimode fibers such as high efficiency of nonlinear optical excitation and high fluorescence collection," say the inventors. "Nonlinear optical feedback signals can be collected in both cores for improved detection efficiency relative to conventional single-mode and multi-mode fibers."
• Title: Injection locked diode lasers
Applicant: Koninklijke Philips Electronics N.V, the Netherlands
International application number: WO 2004/057714
Patent application WO 2004/057714 describes a way to modulate the wavelength of a high-power diode laser. The process involves injecting light from a low-power diode laser into a higher power device. The application also details how this technique could be used to write data to an optical disc. As optical discs contain a layer of photosensitive material into which information is written, changes in the wavelength correspond to variations in the absorption of the material. "The principles of the present invention can be applied to any storage technique in which the absorption of the recording medium changes with the wavelength of the incident light," say the authors.