Design, construction, and operation of a submillimeter waveguide laser system and Stark modulator
Jenkins, James Alan
Wilson, William L.
Master of Science
A submillimeter laser system, consisting of a methanol waveguide laser and its CO^ laser pump, was built. The CQ laser used ZnSe optics and was diffraction grating tuned, making available over 8 lines in the 9.6um and 1.6um bands. The typical output power level was 12W. This CO laser provided the pump radiation for a waveguide laser which used a precision-bored Cu tube to (l) confine the discharge plasma and the pump radiation and (2) serve as a waveguide for the submillimeter radiation field. Cu mirrors placed at the ends of the tube defined the laser cavity. A coupling hole in each mirror allowed 1.6um CO radiation to enter the cavity at one end and 118.8um radiation, generated by a rotational transition in methanol, to leave at the other end. The 3mW of submillimeter light generated was used to study the effects of Stark modulating methanol in a cell through which the light was passed. A 2% modulation index was observed for a Stark cell pressure of 3umHg and a Stark electric field of amplitude 1V/cm and frequency 2Hz. It was found that the Stark effect was linear and that an increase in electric field led to a decrease in submillimeter wave absorption in the cell.