Tuning optical cavities

US7817281B2 · kind B2 · utility

Assignee

• Palo Alto Research Center Incorporated · US

Inventors

• Peter Kiesel · Palo Alto, US
• Oliver Schmidt · Palo Alto, US
• Michael Bassler · Erlangen, DE
• Uma Srinivasan · Poughkeepsie, US

Key dates

• Filing date: Feb 5, 2007
• Grant date: Oct 19, 2010
• Expiry date: Mar 5, 2028

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S3/105
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An inhomogeneous optical cavity is tuned by changing its shape, such as by changing reflection surface positions to change tilt angle, thickness, or both. Deformable components such as elastomer spacers can be connected so that, when deformed, they change relative positions of structures with light-reflective components such as mirrors, changing cavity shape. Electrodes can cause deformation, such as electrostatically, electromagnetically, or piezoelectrically, and can also be used to measure thicknesses of the cavity. The cavity can be tuned, for example, across a continuous spectrum, to a specific wavelength band, to a shape that increases or decreases the number of modes it has, to a series of transmission ranges each suitable for a respective light source, with a modulation that allows lock-in with photosensing for greater sensitivity, and so forth. The optical cavity can be a linear variable filter fabricated on the photosensitive surface of a photosensing component such as a photosensor array or a position-sensitive detector.