In order to measure the electron desity profile on the LHD, a 10-channel laser interferometer has been designed. For the diagnostic application, an optically pumped 119-μm CH3OH laser and a discharge pumped 195-μm DCN laser are under development.
Discharge pumped DCN-laser(195 gm) and CO2 laser pumped CH2F2(185 itm)- and CH3OH (119 gm)-lasers have been developed for plasma diagnostics on LHD. The systems and the characteristics of these lasers are reported.
A new power meter with a sensitive micro-calorimeter has been developed to measure the absolute power of FIR laser. Using this power meter, a calibration of a Scientech power and energy meter of 36 series has been carried out for 337 μm wavelength.