A white-light interferometry scheme to measure wide-wavelengthdispersion of thermo-optic coefficients of optical switch materials

摘要

This paper reports demonstration of a new simple white-light interferometry method for continuous dispersion curves ofthe thermo-optic (TO) coefficients of optical samples. Phase shifts of the interference spectra of the white-lightinterferometer output are measured by changing temperature of an optical sample located in the one of the interferometerarms. A continuous dispersion curve of the TO coefficient of the sample materials over the full wavelength coverageregion of the white light beam is obtained from the phase shift information with the temperature change. This newmethod is tested with a fused silica glass material of well-known optical properties to prove its accuracy by comparingthe measured results with its known TO coefficient values. This continuous dispersion information of the TOcoefficients of new optical materials will be useful for fabrication of the WDM signal processing devices or functionaldevices in multi-wavelengths.