We demonstrate coherent detection of continuous-wave mid-infrared radiation. This radiation is produced by use of conventional difference-frequency mixing and detected via the linear electro-optic effect. The detection process allows for the simultaneous measurement of the amplitude and phase properties of the infrared field. Both processes require an amplitude-modulated optical beam that is derived from the superimposed output of two single-frequency lasers. With appropriate choice of lasers and nonlinear optical crystals, the technique may be applied to any wavelength throughout the far and mid infrared.
© 2002 Optical Society of America
(120.1880) Instrumentation, measurement, and metrology : Detection
(120.2920) Instrumentation, measurement, and metrology : Homodyning
(160.2100) Materials : Electro-optical materials
(190.2620) Nonlinear optics : Harmonic generation and mixing
(190.7220) Nonlinear optics : Upconversion
Hua Cao and Ajay Nahata, "Electro-optic detection of continuous-wave mid-infrared radiation," Opt. Lett. 27, 1779-1781 (2002)