title: Collinear acousto-optic diffraction using two nearby sound frequencies
abstract: Collinear acousto-optic spectrometers with sound consisting of one frequency have a spectral transfer function with many good characteristics, such as a narrow bandwidth, ... the side lobes, however, are rather high. To reduce these side lobes, one can try to apodize the sound in the acousto-optic cell by using a sound wave consisting out of two frequencies. At certain times, this produces a more smoothened sound field in the cell than in the one-frequency case. The resulting transfer function will contain lower side lobes. Also, the influence of all the sound field parameters--the amplitude, frequency difference, and time--on the transmission function is studied. Out of these results, better-performing collinear spectrometers can be designed.
authors.affiliation: Interdisciplinary Research Center, Kortrijk, Belgium. filip.windels@kulak.ac.be
authors.initials: FW
authors.lastname: Windels
authors.initials: VI
authors.lastname: Pustovoit
authors.initials: O
authors.lastname: Leroy