Patent ID: 9476770
Filing Date: 2016-10-25
CPC Classification: G01J,G01N

Claim Text:
1. A system for detecting the presence of a trace chemical in a sample comprising: a laser light source for generating a beam of light; a beam splitter that is operative to split the beam of light into a first beam of light and a second beam of light; a reference cell and a first recording device that are operative to receive the first beam of light; where the first recording device is downstream of the reference cell; a resonator that is operative to receive the second beam of light via a tunable coupler; where the resonator contains the sample that contains the trace chemical; a phase modulator and a second recording device that lie downstream of the resonator and are operative to receive the second beam of light; where the coupler is operative to: a) modulate coupling strength between the resonator and an input waveguide; and b) biasing a coupling between the coupler and the resonator at a critical point; and where an output from the first recording device is compared with an output from the second recording device to determine an amount of the trace chemical.