Microstructured Silicon Based All-Optical Spatial Terahertz Modulator

摘要

Spatial light modulators (SLM), which allow fast imaging with a single detector, are highly demanded for constructing cost-effective, highly sensitive and exceptionally compact terahertz (THz) imager. Here we designed and realized an optical THz-SLM based on micro-structured Si (MS-Si), where the irregular but compactly arranged Si micro-pyramids significantly decrease the reflectivity to ～10% in the broad optical wavelength range of 400–1050nm, meanwhile greatly increases the active area for THz wave modulation. The novel silicon based modulator provides significant advantages over current THz SLMs in modulation bandwidth, speed and depth with the highest modulation depth of 94.17% and speed of 146.6 kHz. With this unique SLM, a reconfigurable, cost-effective and power-efficient imaging system with a single-pixel detector has been demonstrated.