Patent ID: 7403275
Filing Date: 2008-07-22
Classification: G01M

Abstract:
1. A method of testing an optical waveguide to determine a distance in the optical waveguide to an occurrence of interest, the method comprising: at a VCSEL, emitting a wavelength modulated optical signal into a waveguide; receiving at the VCSEL a reflection of the wavelength modulated optical signal, wherein the reflection is caused by an occurrence of interest affecting the waveguide at a particular wavelength and wherein the reflection being received at the VCSEL causes a change in the VCSEL output; detecting the change in the VCSEL output; correlating the change in VCSEL output to a distance in the waveguide, wherein the distance is, at least approximately, a distance to the occurrence of interest; and determining the distance in the optical waveguide to the occurrence of interest based on the correlation of the change in VCSEL output to the distance in the waveguide.