Patent ID: 8350240

Claim:
A device for generating and detecting coherent electromagnetic radiation ( 8 ) in the THz frequency range, comprising an optically parametric oscillator ( 2 ) for generating electromagnetic radiation in the THz frequency range ( 8 ), characterised in that it has a coherent phase-sensitive detector ( 3 , 21 ) for detecting intensity and phase of the electromagnetic radiation ( 8 ) generated by the optically parametric oscillator ( 2 ), wherein the optically parametric oscillator ( 2 ) and the coherent phase-sensitive detector ( 3 , 21 ) are adapted that in operation of the device at least a part of electromagnetic pump radiation ( 12 ) which passes through the optically parametric oscillator ( 2 ) is passed into the coherent phase-sensitive detector ( 3 , 21 ), wherein in the optically parametric oscillator ( 2 ) electromagnetic radiation is at a second frequency different from the frequency of the pump radiation ( 12 ) and from the THz frequency and wherein the optically parametric oscillator ( 2 ) and the coherent phase-sensitive detector ( 3 , 21 ) are adapted that in operation of the device the electromagnetic radiation at the second frequency is incident into the coherent phase-sensitive detector ( 3 , 21 ) in spatially heterodyned relationship with the pump radiation ( 12 ).