Photoelastic properties of lithium tetraborate crystals

Abstract

We report the results of comprehensive studies of the piezo-optic and elasto-optic effects in lithium tetraborate crystals, Li₂B₄O₇. The full matrices of piezo-optic and elasto-optic coefficients are obtained using a recently developed method based on four-point bending. On this basis, we have estimated the acousto-optic figure of merit for Li₂B₄O₇.

Characterization of photoelastic materials by combined Mach-Zehnder and conoscopic interferometry: Application to tetragonal lithium tetraborate crystals

“…POC 66 (1.66 Br [30] or 1.1 Br [ 31 ,32 ] against e.g. − 1.39 Br [26] ), here 1 Br = 1 Brewster = 1 · 10 − 12 m 2 /N. Similar ambiguities are noted also for several other POCs, im .…”

Piezooptic coefficients and acoustooptic efficiency of TGS crystals

“…However, the above AO figure of merit is still comparable or even higher than the corresponding parameters of the other crystals transparent in the ultraviolet spectral region, e.g. quartz, KDP, ADP or Li 2 B 4 O 7 [21,30,31]. It is important that our consideration has dealt with the AO interaction with the fast quasi-longitudinal acoustic wave.…”

Anisotropy of acousto-optic figure of merit in tetragonal crystals with accounting for non-orthogonality of acoustic eigenwave polarizations. 2. The cases of Li2B4O7 and TeO2 crystals

“…[15,16]. In our calculations, we have used the known elastic-stiffness (C 11 = 135.27±0.12, C 12 = 1.09±0.06, C 13 = 31.86±0.10, C 33 = 54.80±0.10, C 44 = 57.39±0.08 and C 66 = 47.38±0.06 GPa [13]) and elasto-optic (p 11 = 0.083±0.003, p 12 = 0.227±0.017, p 13 = 0.227±0.005, p 31 = 0.209±0.011, p 33 = 0.163±0.006, p 44 = -0.0075±0.0061 and p 66 = -0.066±0.002 [17]) coefficients of the Li 2 B 4 O 7 crystals. In the case of TeO 2 crystals, the elastic stiffness coefficients are equal to C 11 = 53.2, C 12 = 48.6, C 13 = 21.2, C 33 = 108.5, C 44 = 24.4 and C 66 = 55.2 GPa, while the elasto-optic coefficients amount to p 11 = 0.0074, p 12 = 0.187, p 13 = 0.34, p 31 = 0.0905, p 33 = 0.24, p 44 = -0.17 and p 66 = -0.0463 [16].…”

“…It is highly resistant to a high-power optical radiation, with the damage threshold being equal to 40 GW/cm 2 [4,5]. The crystal is transparent in the UV spectral range down to 170 nm [5] and represents a promising AO material [6][7][8][9] for operating high-power short-wavelength optical radiation. As shown in our recent work [9], the maximal AOFM for the Li 2 B 4 O 7 crystals can reach the value 3.44×10 −15 s 3 /kg in the visible spectral range.…”