Patent ID: 9194742
Filing Date: 2015-11-24
Classification: G01J,G01N

Abstract:
1. A method of measuring cavity loss of a resonant optical cavity over a range of frequencies by exciting one or a plurality of cavity modes of the cavity in a controlled manner, the cavity having at least two cavity mirrors, one of which is a cavity coupling mirror, using a laser that emits continuous wave laser light, wherein the laser is responsive to optical feedback light emerging from the cavity, and wherein a mean optical frequency of the laser is adjustable over a range of frequencies, the method comprising: coupling the laser light to the cavity via the cavity coupling mirror using mode matching optics, the cavity having a plurality of optical resonance cavity modes that have frequencies within said range of frequencies of the laser; applying to the laser a current having a predetermined current profile so as to adjust the mean optical frequency of the laser and to excite cavity modes in an excitation order responsive to a shape of the applied current profile, said excitation order comprising excitation of multiple desired cavity modes in as non-consecutive order; and detecting dynamics of the intra cavity optical power of light circulating in the cavity after a cavity mode has been excited.