Broadband terahertz radiation produced in an AgGaSe_2 crystal

摘要

The linear and nonlinear optical properties are investigated in a <110>-cut, 485 μm-thick AgGaSe; crystal. The linear optical properties are studied by performing terahertz time-domain spectroscopy measurements, which allow the refractive indices and the extinction coefficients to be calculated for the uniaxial AgGaSe: crystal. Optical rectification measurements are conducted to investigate the crystal's nonlinear optical properties, which produce broadband terahertz radiation pulses having spectral components between 0.02 and 4 THz. Due to the large optical rectification coherence length exhibited by the AgGaSe_2 crystal, in-phase terahertz radiation is generated across the entire length of this 485μm-thick crystal. Therefore, this crystal can be utilized as a source of broadband terahertz radiation in areas such as medicine and security.