Development of short-wavelength far-infrared laser for high density plasmadiagnostics

For high density operation of the large helical device and for a future lar ge plasma machine such as ITER, a powerful 57 mum CH3OD laser pumped by a c ontinuous wave 9R(8) CO2 laser has been developed. The 57 mum (5.2 THz) las er light has been successfully detected by using a GaAs Schottky barrier di ode detector with a corner reflector. For optical windows of the plasma ves sel and the far-infrared laser crystal quartz etalons have been designed un der a concept of a two-wavelength etalon for 119 and 57 mum lights. (C) 200 1 American Institute of Physics.