05 Aug 2004
The pick of this week's patent applications including a lens that efficiently couples light into an optical fiber.
• Title: Apparatus for improved fiber optic coupling efficiency
Applicant: The Hong Kong Applied Science Technology Research Instituted Co. Ltd, Hong Kong
International application number: WO 2004/063784
A lens that efficiently couples a beam from a light source into an optical fiber is discussed in patent application WO 2004/063784. The lens has both a curved reflecting surface and a focusing surface. "The lens is positioned to receive and internally reflect the beam of light from the optical device toward the focusing surface," explain the authors. "The focusing surface in turn focuses the reflected beam into the end of an optical fiber." They add that the curved surface could have a reflective coating which splits off a portion of the beam for monitoring.
• Title: An image projecting device and method
Applicant: Explay Ltd, Israel
International application number: WO 2004/064410
An Israeli firm has applied to patent a miniature image projector. The device contains a light source, a reflective or transmissive spatial light modulator (SLM) and a set of magnification optics on the output side of the SLM. According to the firm, the light source may be made up of several emitters which in turn generate a number of beams covering different wavelength ranges. "The light source system may comprise a multi-mode laser, thereby reducing a speckle effect in an integrated speckle pattern produced by multiple modes compared with a single mode," say the applicants.
• Title: System for detection of wafer defects
Applicant: Negevtech Ltd, Israel
International application number: WO 2004/063698
Finding defects in a wafer could become easier, thanks to an electro-optical system described in patent application WO 2004/063698. The system uses a short-pulsed laser to illuminate the wafer which is constantly moving across the field of view of an imaging system. "The continuously moving wafer is illuminated by a laser pulse of duration significantly shorter than the pixel dwell time, such that there is no image smear during the wafer motion," say the inventors. They add that their application describes a fiber-optic illumination system, a way to auto-focus the wafer imaging system and a method to remove repetitive features in the image using Fourier plane filtering.