Tunable acousto-optic filter utilizing acoustic beam walkoff in crystal quartz

Abstract

A new configuration of a tunable acousto-optic filter utilizing acoustic beam walkoff in crystal quartz is described. By changing the acoustic frequency from 54 to 175 MHz, tuning of optical wavelength from about 650 to 250 nm is obtained in a single filter.

Acousto-Optic Devices Based on Potassium Rare-Earth Tungstates Laser Crystals

“…The AOTF of this geometry (Fig. 4) is characterized with an acoustic column walk-o like the collinear AOTF on α-SiO 2 [9]. Among the four discussed materials (Table), KYbW crystals can provide the best spectral resolution δλ ∼ 1/∆n because of the highest refractive index dierence ∆n = n p − n m .…”

Influence of Strong Acoustic Anisotropy on Reflection of Bulk Acoustic Waves in Crystals

“…In this paper, the acousto-optic material paratellurite TeO 2 and calomel Hg 2 Cl 2 were chosen for the analysis. These materials are characterized by the pronounced elastic anisotropy so that the value of the acoustic phase velocity V strongly depends on a direction of propagation [3][4][5][6][7][8][9]. In particular, the slow-shear acoustic wave propagating in the XY plane at the angle θ = 45 • relatively to the axis X or Y possesses the extraordinary low phase velocity values V = 616 m/s, for paratellurite, and V = 347 m/s, for calomel.…”

“…The elastic waves propagating in the anisotropic crystals, such as paratellurite, and calomel are characterized by large walk-off angles ψ between the phase V and the group V g velocities of ultrasound [1][2][3][4][5][6][7][8][10][11][12][13][14][15]. It may be shown that the walk-off angle ψ between the acoustic wave vector K and the Poynting vector in these materials may exceed dozens of degrees, e.g.…”

“…It may be shown that the walk-off angle ψ between the acoustic wave vector K and the Poynting vector in these materials may exceed dozens of degrees, e.g. ψ > 70 • [1][2][3][4][5][6][7][8][15][16][17][18], while in BaTiO 3 , the angle is limited to ψ > 40 • . This characteristic feature of the waves may cause the strange reflection of the acoustic energy incident on a free boundary separating the materials and the vacuum.…”

“…The new effects manifest themselves in the most impressive manner in the modern acousto-optic materials such as paratellurite TeO 2 and calomel Hg 2 Cl 2 as well as in other crystals possessing the extremely strong anisotropy of their elastic properties [1][2][3][4][5][6][7][8][9]. It should be noted that growth and fabrication of these unique crystalline materials was to a great extent stimulated by requirements of acousto-optics, optical communication, and laser technology [1][2][3][4][5][6][7][8][9]. In this paper, the acousto-optic material paratellurite TeO 2 and calomel Hg 2 Cl 2 were chosen for the analysis.…”