Growth of the new long-wave infrared nonlinear crystal PbIn₆Te₁₀

The new far-IR nonlinear crystal material PbIn₆Te₁₀ has great application potential among 14-25 μm even more than 25 μm because of its special optical properties, including clear transparency(1.3-31 μm), large nonlinear coefficient(d₁₁=51 pm/V) and suitable birefringence(~0.05). The phase diagram analysis combined with the experiment was used to select the appropriate group distribution ratio, the PbIn₆Te₁₀ polycrystal was synthesized by high temperature single-temperature zone method(STZM), and single crystal with size of φ11 mm×55 mm was grown by Bridgman Method. The as-grown crystals were characterized by X-ray diffraction, X-ray rocking curve, infrared transmittance et al. XRD analysis indicates that the crystal has a trigonal structure, the lattice constants of a, b and c are 1.496 1 nm and 1.825 7 nm, respectively. The as-grown crystal is crystallized well (FHWM=0.253°), the infrared transmission is above 50% in the spectral region of 2.5-25 μm, the coefficient is 0.3-0.6 cm⁻¹.