High resolution terahertz laser spectrometer

The terahertz range of the electromagnetic spectrum (100 GHz - 10 THz) represents a gap between electronic and photonic devices. The advent of some THz-wave sources (difference-frequency generation by near-infrared lasers photomixed on semiconductor substrates, ultra-short pulse generation with photoconductive antennas pumped by femtosecond lasers or terahertz parametric oscillation) open new trends in broadband communications or imaging. Two approaches (metallic meshes and Bragg reflectors) are competitive in order to build low-cost high-finesse devices required in high resolution terahertz spectroscopy experiments.