Acousto-optic tunable filter using phased-array transducer with linearized RF to optical frequency mapping

摘要

We present an optimized design of an acousto-optic tunable filter (AOTF) using a phased-array transducer for a spectrally-multiplexed ultrafast pulse-shaping RF beamformer application. The momentum-space interaction geometry is used to optimize an AOTF using acoustic beam-steering techniques in combination with acoustic anisotropy in order to linearly map the applied RF frequency to the filtered output optical frequency. The appropriate crystal orientation and phased-array transducer design are determined to linearize the RF to optical frequency mapping even in the presence of optical dispersion of the birefringence. After optimizing the phased-array transducer, acoustic anisotropy, and optical anisotropic diffraction geometry, the designed AOTF will compensate for the birefringent dispersion of TeO_2 to give a linear modulation of RF frequencies onto the corresponding optical frequencies. This linearized frequency mapped AOTF is required for a squint-compensated, wavelength-multiplexed, optically processed RF imager.