Solid-state laser chip based on a KGd(WO_4)_2:Nd^3+ crystal with semiconductor end pumping and passive Q-switching, lasing at wavelength 135 μm

Abstract

We studied a miniature laser source with an end-fed semiconductor pump in pulsed-periodic and cw mode; the pump had an active element that consisted of a KGd(WO4)2:Nd3+ crystal lasing at wavelength 1.35 μm. The laser power was studied as a function of pump-pulse width. It was shown that the output power from a chip laser of this type is capable of reaching 0.25 W in pulse-periodic mode with a pump power of 1.9 W, and 0.06 W in Q-switched mode at a pump power of 1.9 W. The effect of optical cavity length on the width of the lasing pulse from the laser was also studied. The behavior of a laser in which the cavity consisted of only two elements—a KGd(WO4)2:Nd3+ active element with a backstop mirror deposited on one end, and a YAG:V3+ passive laser gate with an exit mirror deposited on one end. The cavity in this two-element laser chip was 5 mm long. It was shown that such a laser chip can have a laser-pulse width of 7 ns or less.