Increasing the Angular Sweep Range of Laser Beam in the Anisotropic Acousto-Optic Deflector

Method of increasing the angular sweep range of beam in the anisotropic acoustooptic deflector in paratellurite by increasing the incidence angle of the diffracted beam on the output side of the deflector is proposed. On the basis of vector diagrams the calculation methods of the acoustooptic interaction geometry in an paratellurite crystal for the lower and upper branches of diffraction under specified range of operating frequency of control is presented. The ratio for calculation of light-acoustic line design of the proposed unit and linearization of the beam deflection angles at the deflector output under condition of incident and emerging beams parallelism are obtained. It is shown that for the laser beam with a radiation wavelength 1,064 μm maximum angular sweep range of beam reaches 5.7° at the deflector output under condition of incident and emerging beams parallelism and 7.5° in case of deviation from this condition, which is confirmed by experimental studies.

References

[1] Bondarenko D.A., Karasik V.E., Semenkov V.P. Research regime of the laser beam diffraction using a linearly frequency-modulated acoustic waves in an anisotropic acousto-optic deflector. Vestn. Mosk. Gos. Tekh. Univ. im. N.E. Baumana, Priborostr., Spetsvyp. "Sovremennye problemy optotekhniki" [Herald of the Bauman Moscow State Tech. Univ., Instrum. Eng., Spec. Issue "Modern optical engineering problems"], 2011 (in Russ.).

[2] Dixon R.W. Acoustic diffraction of light in anisotropic media. IEEE Journ. Quant. Electr., 1967, vol. QE-3, no. 2, pp. 85-93.

[3] Magdich L.N., Molchanov V.Ya. Akustoopticheskie ustroystva i ikh primenenie [Acousto-optic devices and their application]. Moscow, Sov. Radio Publ., 1978. 112 p.

[4] Korpel A. Acousto-optics. N.Y. and Basel: Marcel Dekker, Inc., 1988. 265 p. (Russ. ed.: Korpel A. Akustooptika, per. s angl. Moscow, Mir Publ., 1993. 240 p.)

[5] Semenkov V.P. The anisotropic acousto-optic deflector for uniaxial crystals with optical activity. Zh. Tekh. Fiz. [Tech. Phys. The Russ. J. Appl. Phys.], 1981, vol. 51, no. 10, pp. 2090-2095 (in Russ.).

[6] Warner A.W., White D.L., Bonner W.A. Acousto-optic light deflectors using optical activity in paratellurite. Appl. Phys. Letters, 1972, vol. 43, no. 11.

[7] Balakshiy V.I. Fizicheskie osnovy akustooptiki. [Physical basis of optoacoustics]. Moscow, Radio i Svyaz’ Publ., 1985. 280 p.

[8] Yano T. TeO2 anisotropic Bragg light deflector without midband degeneracy. Appl. Phys. Letters, 1975, vol. 26, no. 12, pp. 689-691.

[9] Magdich L.N., Molchanov V.Ya. About the theory of acousto-optical interaction in a strong field. Opt. Spektrosk. [Optics and Spectroscopy], 1980, vol. 48, no. 1, pp. 159-159.

[10] Semenkov V.P, Magdich L.N., Bondarenko D.A. Akustoopticheskiy anizotropnyy deflektor [Acousto-optic anisotropic deflector]. Patent RF, no. 2462739, 2012.