Abstract: An agile optical sensor based on spectrally agile heterodyne optical interferometric confocal microscopy implemented via an ultra-stable in-line acousto-optic tunable filter (AOTF) based interferometer using double anisotropic acousto-optic Bragg diffraction. One embodiment uses a tunable laser as the light source while other embodiments use a broadband source or a fixed wavelength laser as the source. One embodiment uses anisotropic diffractions in an AOTF to generate two near-collinear orthogonal linear polarization and slightly displaced beams that both pass via a test sample to deliver highly sensitive sample birefringence or material optical retardation measurements. A spherical lens is used to form focused spots for high resolution spatial sampling of the test object. The laser and AOTF tuning allows birefringence measurements taken at different wavelengths, one at a time.

Abstract: An agile optical sensor based on spectrally agile heterodyne optical interferometric confocal microscopy implemented via an ultra-stable in-line acousto-optic tunable filter (AOTF) based interferometer using double anisotropic acousto-optic Bragg diffraction. One embodiment uses a tunable laser as the light source while other embodiments use a broadband source or a fixed wavelength laser as the source. One embodiment uses anisotropic diffractions in an AOTF to generate two near-collinear orthogonal linear polarization and slightly displaced beams that both pass via a test sample to deliver highly sensitive sample birefringence or material optical retardation measurements. A spherical lens is used to form focused spots for high resolution spatial sampling of the test object. The laser and AOTF tuning allows birefringence measurements taken at different wavelengths, one at a time.