Active and passive optical cavity characteristics measurer

摘要

Described are procedure and technique capable of analyzing cavity spectra, making coefficients of total and diffracted cavity loss measurements, reflectivity measurements of low- loss highly reflecting mirror coatings and gain measurements of active substance. Measurer also makes it possible to control a level of selection, a quality of mirrors alignment and an accuracy of cavity monoblock making. The apparatus analyzes transmission or reflectivity spectra of controlled cavity, directly measure output pulse width proportional to cavity linewidth (FWHM intensity) and time proportional to frequency distances apart the transmission or reflectivity lines. We develop the theoretical framework for the device and discuss in what conditions and to what extent the output pulse width and the time proportional to frequency distances apart the lines measurements represents a true measure of cavity parameters. Current apparatus provides a cavity loss and gain resolution 0.0001 and spectral resolution 10 kHz.