Patent ID: 8610073

Claim:
A monochromatic wavelength variable terahertz wave generation/detection system comprising: one excitation light source that generates excitation light of monochromatic wavelength; a wavelength variable terahertz wave source that inputs the excitation light to satisfy a first angle phase matching condition suitable to generate a terahertz wave and that generates the terahertz wave; a terahertz wave phase control optical system that leads the terahertz wave generated from the wavelength variable terahertz wave source to a measurement sample; a nonlinear light conversion terahertz wave detector that inputs the terahertz wave passed through the measurement sample and the excitation light to satisfy a second angle phase matching condition and that converts the wavelength of the inputted terahertz wave to form a light wave; a light detector that detects the light wave outputted from the nonlinear light conversion terahertz wave detector; an excitation light phase control optical system including, on a light path of the excitation light, an optical element capable of changing an incidence angle of the excitation light to a generation point of the terahertz wave in the wavelength variable terahertz wave source and an incidence angle of the excitation light to an incidence point of the terahertz wave in the nonlinear light conversion terahertz wave detector to set both the generation point and the incidence point at the same time on the focal points in a confocal optical system; and a control apparatus that controls at least one of the wavelength variable terahertz wave source, the terahertz wave phase control optical system, the nonlinear light conversion terahertz wave detector, the light detector, and the excitation light phase control optical system.