Device for measurement of optical wavelengths

US6097487A · kind A · utility

Assignee

• OPTOPLAN AS · NO

Inventors

• Jon Thomas Kringlebotn · Trondheim, NO
• Dag Thingbo · Vikhammer, NO
• Hilde Nakstad · Trondheim, NO

Key dates

• Filing date: Jul 29, 1999
• Grant date: Aug 1, 2000
• Expiry date: Jul 29, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G01J9/0246
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A device for accurate and repeatable measurements of optical wavelengths, including an interrogation broadband light source (1) and a tuneable optical filter (2). A first part of the light is, in either order, transmitted through the filter (2) and reflected from, or transmitted through, at least one fibre Bragg grating (5) with known Bragg wavelength, providing an absolute wavelength reference, and directed to a first detector (7). A second part of the light is, in either order, transmitted through the filter and transmitted through, or reflected from a Fabry-Perot filter (8) with fixed and known free spectral range, creating a comb spectrum sampling the interrogation source spectrum to provide an accurate frequency/wavelength scale.