| Abstract Scope |
In<sub>x</sub>Ga<sub>1-x</sub>Sb and In<sub>x</sub>Ga<sub>1-x</sub>As are ternary semiconductor materials widely used in optical fiber communication, lasers, optical switches, and infrared optical detectors. Because of the crystal lattice constant mismatch, it has been difficult to grow uncracked thick In<sub>x</sub>Ga<sub>1-x</sub>Sb and In<sub>x</sub>Ga<sub>1-x</sub>As layers on binary compounds. Therefore, previous studies were focused on thin film In<sub>x</sub>Ga<sub>1-x</sub>Sb and In<sub>x</sub>Ga<sub>1-x</sub>As epitaxial layers, and thus most optical parameters of bulk In<sub>x</sub>Ga<sub>1-x</sub>As and In<sub>x</sub>Ga<sub>1-x</sub>Sb crystals are unknown. Recent advances in crystal growth techniques have allowed successful growth of good melt-grown bulk ternary In<sub>x</sub>Ga<sub>1-x</sub>Sb and In<sub>x</sub>Ga<sub>1-x</sub>As crystals using the vertical Bridgman technique. In this work, optical properties of In<sub>x</sub>Ga<sub>1-x</sub>Sb and In<sub>x</sub>Ga<sub>1-x</sub>As bulk crystals have been investigated using Michelson and Fabry-Perot interferometers and Fourier transform infrared spectroscopy. The refractive index value, n, the thermo-optical coefficient, dn/dT, and absorption coefficient were measured as a function of wavelength, temperature, and indium mole fraction x, all of which are very important parameters in optoelectronic device applications. |