Patent ID: 9025157
Filing Date: 2015-05-05
Classification: G01D,G01J,G01K,G01L,G02B

Abstract:
1. An optical device comprising: a fiber Bragg grating comprising a substantially periodic refractive index modulation along a length of the fiber Bragg grating, wherein the fiber Bragg grating has a power reflection spectrum as a function of wavelength, a power transmission spectrum as a function of wavelength, and a group delay spectrum as a function of wavelength; a narrowband optical source in optical communication with the fiber Bragg grating and configured to transmit light to the fiber Bragg grating such that a transmitted portion of the light is transmitted along the length of the fiber Bragg grating and a reflected portion of the light is reflected from the fiber Bragg grating, wherein the power transmission spectrum as a function of wavelength comprises one or more resonance peaks, each comprising a local maximum and two non-zero-slope regions with the local maximum therebetween; and at least one optical detector configured to detect an optical power of the transmitted portion of the light, the reflected portion of the light, or both the transmitted portion of the light and the reflected portion of the light, wherein the light has a wavelength at a non-zero-slope region of a resonance peak of the one or more resonance peaks, wherein the resonance peak is selected such that one or more of the following quantities, evaluated at the resonance peak, is at a maximum value: (a) the product of the group delay spectrum and the power transmission spectrum and (b) the product of the group delay spectrum and one minus the power reflection spectrum.