Alleviation of photoinduced damage in Gd_xY_1–xCa_4O(BO_3)_3 at elevated crystal temperature for noncritically phase-matched 355-nm generation

Abstract

We developed a Gd(x)Y(1-x)Ca(4)O(BO(3))(3) (GdYCOB) crystal for control of optical birefringence. GdYCOB crystals were successfully used to generate noncritical phase-matched (NCPM) second and third harmonics of 1064-nm lights. However, we observed degradation of third-harmonic-generation (THG) output power and distortion of the beam pattern as a result of photoinduced damage and thermal dephasing. The photoinduced damage was classified into two types. One was gray-track and the other was photorefractive damage. It seems that these types of damage were similar to the types of damage that occurred with KTiOPO(4) and LiNbO(3) crystals. We tried to circumvent this problem by crystal heating. Photoinduced damage of GdYCOB was overcome by elevation of the crystal temperature, and NCPM THG (355-nm) output power from heated GdYCOB increased to 9 mW (62.5 kHz).

Growth and non-critical phase-matching frequency conversion properties of LaxY1−xCOB crystals

“…This phenomenon was also observed for Gd x Y 1−x COB during the large-energy THG process, which was reported to be associated with the intrinsic absorption of the Gd 2+ /Y 2+ colour center induced by oxygen defects. 39,46,47 The THGinduced gray-track in the La 0.140 Y 0.860 COB crystal was successfully removed after thermal annealing at 150 °C for 15 h in a muffle furnace, as shown in Fig. 12(b).…”

“…[31][32][33][34][35][36] Additionally, the type-I NCPM third-harmonic-generation (THG) of 1064 nm has also been demonstrated. 31,[37][38][39] Besides the YCOB crystals, when the Ca 2+ ions of LaCOB crystals are partially substituted by Sr 2+ ions, blue lights in the range of 495-473 nm were observed through type-I NCPM SHG of the corresponding fundamental wavelengths. 40 The wide waveband NCPM attributes of RECOB-type crystals, as the optimum PM style in the NLO domain, have aroused popular and sustained research interest all over the world.…”

Other Borate Crystals

“…The phase-matching angles are (, w) ¼ (90 , 73.2 ) and (58.7 , 90 ) in the x-y-and y-z planes. In general, the THG performance of YCOB has been limited by photo-induced damages such as gray track formation, as described in Section 4.5.2.1 [54]. In general, the THG performance of YCOB has been limited by photo-induced damages such as gray track formation, as described in Section 4.5.2.1 [54].…”

Bulk growth and nonlinear optical properties of thulium calcium oxyborate single crystals

“…34,35 Moreover, the birefringence of GdCOB crystals was reported to be adjustable by doping with trivalent ions, such as Y 3+ , Lu 3+ , Sc 3+ , etc., thus a variety of wavelengths were obtained by noncritical phase matching (NCPM). [36][37][38][39][40] More interestingly, the d eff values of YCOB and GdCOB crystals were reported to increase when doped with Tm 3+ , Yb 3+ , Bi 3+ and Li + ions. 41,42 Based on the previous reports, it is evident that the cations, including trivalent cations and other cations, contributed to the improvement of NLO optical properties of ReCOB crystals.…”