Submillimeter laser interferometer for high density plasma diagnostic

There are presented the results of investigation of the one-channel homodyne laser interferometer λ = 119 μm made on the basis of the hollow dielectric beamguide and quasioptical functional devices. The interferometer is designed for determination of the plasma electron density of the TOKAMAK-7. The density response threshold is 0.7% from the expected plasma density and the phase difference measurement total error is 5 degrees