The resonator of the terahertz laser with smooth adjustment coupling

The transmittance of a coupling mirror strongly influences the power and efficiency of the laser. Optimal index of coupling can be various on different laser operating modes and consequently, resonators with tuned coupling sometimes required. We have developed the terahertz laser resonator with smooth coupling change. Coupling change can be carried out directly while the laser operation. Coupling coefficient changes about two times within itpsilas range. Lower and higher values of the coefficient depend on the size of an aperture in a metal coupling mirror. The radiation beam cross section does not change during the adjustment.