Optical measurement of carrier properties for InSb

Carrier properties of n-type InSb doped by tellurium at the liquid nitrogen temperature have been measured using the transmission of millimeter wave (119.3 GHz) along a magnetic field up to 4 T in the n-type InSb. Since the wavelength of the millimeter wave in the n-type InSb is generally shorter than that in vacuum (1.26 mm), samples with thicknesses less than 1 mm have been used for the measurement. In the n-type InSb, the millimeter wave injected with the linear polarization has been converted into the helicon wave with the right-hand circular polarization. The helicon wave interacts with an electron and shows the electron cyclotron resonance and its propagation speed depends on the electron density. By studying the dispersion relation from the transmission of the millimeter wave through the n-type InSb, the electron density and effective mass has been estimated.