Lasing in zinc selenide single crystals pumped by high-voltage subnanosecond pulses

The action of subnanosecond high-voltage pulses (U = 50 — 200 kV, t_p = 100 — 500 ps) on 1 — 2-mm-thick plane—parallel ZnSe plates is studied. A sample was placed between a cathode and a circular anode. A discharge propagated along the lines of force of the electric field. Lasing at 480 nm appeared at the discharge front and opposite to the cathode. The average propagation velocity of the discharge achieved 5 × 10⁸ cm s^-1, the pulse power was 600 W, and the radiation divergence did not exceed 2 — 3°. No streamer discharges oriented along crystallographic directions were observed.