Laser Tuning by spectrally dependent spatial filtering

US6959024B2 · kind B2 · utility

Assignee

• Picarro, Inc. · US

Inventors

• Barbara Paldus · Atherton, US
• Jinchun Xie · Cupertino, US
• Robert Lodenkamper · Rancho Palos Verdes, US
• David M. Adams · Greenville, US
• Eric R. Crosson · Mountain View, US
• Alexander Katchanov · Sunnyvale, US
• Grzegorz Pakulski · Woodlawn, CA
• Chris W. Rella · Sunnyvale, US
• Bruce Richman · Sunnyvale, US
• Serguei Koulikov · Los Altos, US

Key dates

• Filing date: Dec 2, 2002
• Grant date: Oct 25, 2005
• Expiry date: Apr 1, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S5/142
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A laser tuning mechanism which embodies “spectrally dependent spatial filtering” (SDSF) and contemplates two key elements of the tuning mechanism. The first element of the SDSF tuning mechanism is a spectrally dependent beam distortion (i.e. alteration of the amplitude and/or phase profile of the beam) provided by an SDSF tuning element in a laser cavity. The second element of the SDSF tuning mechanism is an intracavity spatial filter which makes the round trip cavity loss a sensitive function of both beam distortion and cavity alignment. Such a laser can be aligned so that a specific beam distortion, which is provided by the SDSF tuning element at a tunable wavelength, is required to obtain minimum round trip cavity loss, thereby providing tunable laser emission. A preferred embodiment of the SDSF tuning mechanism is an external cavity semiconductor laser having a zeroth order acousto-optic tuning element.