Diffraction limited CW optically pumped lasers

The far infrared spectral characteristics of inductive metal mesh dielectric hybrid mirrors were investigated. From experimental and theoretical studies, the mirrors were found to exhibit etalon effects due to the finite Si substrate thickness and to have two separate diffraction conditions. With grid spacinggand substrate index of refractionn, forn^{-1} < g/lambda < 1the mirrors diffract in transmission while forg/lambda > 1the mirrors diffract both in transmission and reflection. Using both inductive and capacitive mesh mirrors, EH11outputs have been obtained at the milliwatt level in the range 70 μm to 1.2 mm. Powers in excess of 10 mW were obtained from CH3OH at 96 and 118 μm, HCOOH at 393 μm, CH3I at 447 μm, and CH3F at 496μm.