InGaAs bow-tie diodes for terahertz imaging: low frequency noise characterisation

摘要

Noise characteristics of bow-tie InGaAs diodes in forward and backward directions were measured in frequency rangefrom 10 Hz to 20 kHz at room temperature. It was found that the spectral density of voltage fluctuations changes withfrequency approximately as 1/if/i, indicating that origin of noise is superposition of generation and recombinationprocesses in defects of the structure. It was determined that the dependence of spectral density of current fluctuation oncurrent in backward and forward directions at different frequencies exhibits asymmetry which reflects non-uniformelectric field distribution within the structure. As both noise and sensitivity increase with bias current, optimal conditionsfor device operation are discussed.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.