Self-mixing imaging using a terahertz quantum cascade amplifier

We demonstrate a terahertz imaging system utilizing self-mixing in a 2.9 THz quantum cascade amplifier, through the use of an anti-reflection coated silicon lens to completely suppress lasing action. The fully exploited optical gain of the quantum cascade amplifier allows induced voltage perturbations to be spatially mapped with a signal to noise ratio of up to 55 dB and an acquisition rate of up to 20,000 pixels per second.