New nonlinear optical crystal K_2Al_2B_2O_7

Structure and Optical Properties of K0.67Rb1.33Al2B2O7 Crystal

“…Based on the scissor-corrected electron band structure, the imaginary part of the dielectric function is calculated and the real part of the dielectric function is determined using the Kramers-Kronig transform, from which the refractive indices n (and the birefringence ∆n) is obtained. Furthermore, the second order susceptibility χ (2) and the second harmonic generation (SHG) coefficients d ij are calculated using an expression originally proposed by Rashkeev et al [33], and developed by Lin et al [34,35]. The second-order susceptibility χ ijk is represented as:…”

“…where χ ijk (VE) and χ ijk (VH) denote the contributions from virtual-electron processes and virtual-hole processes, respectively, and χ ijk (two bands) gives the contribution from two band processes to χ (2) . The formulas for calculating χ ijk (VE), χ ijk (VH) and χ ijk (two bands) are as follows: …”

“…K 2 Al 2 B 2 O 7 (KABO) was first reported as a new nonlinear optical crystal by both Hu and Ye in 1998 [1,2]. It crystallizes in the space group of P321 with cell parameters a = b = 8.55800 (2), c = 8.45576(3) (z = 3).…”

“…It crystallizes in the space group of P321 with cell parameters a = b = 8.55800 (2), c = 8.45576(3) (z = 3). It possesses some good nonlinear optical NLO properties, such as a wide transmittance ranging from 180 nm to 3600 nm and a moderate birefringence (∆n = 0.074@1064 nm) [3][4][5][6].…”

Crystal Growth and Associated Properties of a Nonlinear Optical Crystal—Ba2Zn(BO3)2

“…The intense research on the NLO phenomena of borates was triggered by the second-harmonic generation (SHG) reported on β-BaB 2 O 4 (β-BBO) and LiB 3 O 5 (LBO) in the late 1980s [7,8]. Thereafter, a variety of NLO borate materials have been discovered, such as BaZn 2 (BO 3 ) 2 [9], CsB 3 O 5 (CBO) [10], Ba 2 Zn(BO 3 ) 2 [11], KBe 2 BO 3 F 2 (KBBF) [12], Sr 2 Be 2 B 2 O 7 (SBBO) [13], CsLiB 6 O 10 (CLBO) [14], K 2 Al 2 B 2 O 7 (KABO) [15], BaAl 2 B 2 O 7 (BABO) [15], LiAB 4 O 7 (A = K, Rb) [16], M 2 B 5 O 9 X (M = Pb, Ca, Sr, Ba; X = Cl, Br) [17], MBi 2 B 2 O 7 (M = Ca, Sr) [18], Ca 5 (BO 3 ) 3 F [19], BiAlGa 2 (BO 3 ) 4 [20], Bi 2 ZnOB 2 O 6 [21], Ba 3 Sr 4 (BO 3 ) 3 F 5 [22], BaMBO 3 F (M = Zn, Mg) [23], M 3 B 6 O 11 F 2 (M = Sr, Ba) [24], K 3 [33], Li 4 Sr(BO 3 ) 2 [34] and K 3 Ba 3 Li 2 Al 4 B 6 O 20 F [35]. Despite these new borate-based NLO materials, β-BBO, LBO and CLBO are still the most frequently used NLO crystals in UV region, which is attributable to the difficulties of growing high quality crystals or the low transmittance in the UV region.…”