Continuously tunable submillimeter wave source

A method for spanning the 100−1000−μ portion of the spectrum with continuously tunable coherent radiation is described. The approach is based upon laser light scattering from the long−wavelength side of the A1−symmetry soft mode in LiNbO3. In contrast with other techniques, this method uses a single fixed−frequency pump source, requires no magnetic field, provides continuous rather than discrete tuning, can cover most of the 100−1000−μ range, operates at room temperature, and is simple to tune. The experimental data show that tuning was obtained from approximately 150 to 700 μ.