Beta Barium Borate (b-BaB₂O₄ or BBO)

I. Introduction

Beta Barium Borate (b-BaB₂O₄ or BBO) is one of the most outstanding nonlinear optical crystals which has the following unique properties: wide transparency region (from 0.19mm in UV to 3.5mm in NIR) and phase matching range (0.41~ 3.5mm), larger nonlinear coefficient, high damage threshold (>10GW/cm² for 1.3ps 1.064mm), excellent optical homogeneity (Dn~10^-6/cm) and large thermal acceptable bandwidth (~55^oC).

As a result of above obvious advantages, BBO perfectly suits frequency conversions of highpeak or average power laser radiation and harmonic generations in VIS and UV. Typical applications are listed as follows: SHG, THG, 4HG and 5HG harmonic generations of Nd: YAG and Nd:YLF lasers; (SHG, THG, and 4HG harmonic generations of Ti:Sapphire and Alexandrite lasers; (frequency-doubling, -tripling and -mixing of Dye lasers; (frequency-doubling and -tripling of ultrashort pulse Ti:Sapphire and

Dye lasers; (frequency-doubling of Argon ion, Cu-vapor and Ruby lasers. Both Type I

Fig. 1  BBO SHG Tuning Curves

and Type II phase-matching can be obtained by angle-tuning. The BBO phase- matching angles of frequency doubling dependence on input radiation wavelength is shown in Fig. 1.

Wide transparency range and high effective nonlinearity make BBO one of the most suitable materials for applications in broadly tunable optical parametric amplifiers (OPA) and optical parametric oscillators (OPO).

By using improved flux growth methods, Beijing Gospel OptoTech Co. (GOT) has grown up to f130x30mm BBO crystal boules of high quality. As large as 15x15x20 mm³ finished devices with high optical quality are fabricated and supplied steadily. Advanced techniques of crystal growth and fabrication, b production capability as well as strict quality control system, ensure us the first choice and reliable supplier to not only R&D users but commercial and industrial customers in global market.