Patent ID: 9116042
Filing Date: 2015-08-25
Classification: G01J,G01N

Abstract:
1. Apparatus for performing cavity ring-down spectroscopy (CRDS), the apparatus comprising: a traveling-wave cavity having forward and backward optical modes that propagate in opposite directions in the traveling-wave cavity; an optical source capable of providing optical source radiation to the optical cavity; an optical detection unit that receives a forward mode optical signal from the cavity and a backward mode optical signal from the cavity and provides one or more electrical detector signals derived from the forward mode and backward mode optical signals; an optical circulator configured to separate the source radiation from the backward mode optical signal; and a processor that receives the electrical detector signals and provides a cavity loss derived from the one or more electrical signals; wherein the processor derives a ring-down time from the electrical detector signals and wherein the cavity loss is derived from the ring-down time.