Design and analysis of a noncollinear acousto-optic tunable filter

Abstract

The design of the noncollinear acousto-optic tunable filter (AOTF) is commonly based on the parallel tangents momentum-matching condition. Previous studies either have used an approximation of the birefringence of the interaction material or have ignored the rotatory property of TeO(2). These approaches would obviously decrease the accuracy of designing an acousto-optic tunable filter (AOTF). We introduce an analysis method of calculating the optimum incident optical angle. Besides, an appropriate optical wedge on the output optical facet is designed to reduce the wavelength dependence of the diffracted beam angle, which is very significant in practical applications of AOTF.

AOTF-Based Spectral Imaging for Balloon-Borne Platforms

“…Noncollinear AOTFs are used for numerous applications that require imaging with spectral discrimination, including microscopy, hyperspectral imaging, and spectroscopy. Their design principles have been reviewed in papers extending back several decades (Chang, 1974;Yano & Watanabe, 1976;Smith et al, 1987;Gass & Sambles, 1991;Glenar et al, 1994;Gupta et al, 2002;Georgiev et al, 2002;Zhang et al, 2007). They are made of crystals whose optical properties are altered in the presence of an acoustic wave (e.g.…”

Analysis of the Spectral Resolution of a TeO2 based Noncollinear Acousto-Optic Tunable Filter

“…σ is relevant with specific rotation ρ by σ = λρ/2πn o . σ and ρ have wavelength dependence [4]. n o and n e are the ordinary and extraordinary refractive indices in the direction perpendicularly to the optical axis, respectively.…”

“…The unit of λ 0 is micron in (3) and (4). Under the momentum-matching condition, the wave-vector propagation polar angles are,…”

“…The acoustic wave can be generated when a radio frequency signal (rf) is applied to a piezoelectric transducer bonded on the birefringent material, so a change in the applied rf produces a variation in the acoustic wave frequency. Previous studies had confirmed that considering the birefringence of the interaction material and its rotatory property was an effective method of increasing the accuracy of the design obviously [4,5]. The spectral resolution is a key index of evaluating the performance of an AOTF for the actual applications.…”

“…The spectral resolution is a key index of evaluating the performance of an AOTF for the actual applications. However, the previous expression of the spectral resolution which had been widely used is inaccurate for the neglect of the rotatory property [4][5][6][7]. Thus, in this letter, we give an exact expression of the spectral resolution in order to keep up the higher demand for the accurate evaluation of the performance of AOTF.…”