All-solid-state high-power slab laser based on phonon band edge emission

An all-solid-state high-power slab laser based on phonon band-edge emission, comprising a pumping source, a focusing system, a resonant cavity and a self-frequency-doubling crystal in the resonant cavity;

• wherein the pumping source, the focusing system and the resonant cavity are successively arranged along an optical path;
• the resonant cavity is located at an output end of the focusing system;
• the self-frequency-doubling crystal is a Yb-doped ReCa4O(BO3)3 (ReCOB) crystal where Yb is ytterbium, Re is another rare earth element consisting of Gd or La, and COB is calcium oxyborate, and wherein the Yb-doped ReCOB crystal is Yb-doped GdCOB or Yb-doped La COB, or a combination of the two;
• wherein a light transmission direction of the self-frequency-doubling crystal is a lengthwise direction thereof, and wherein the self-frequency-doubling crystal has a length of 6 mm-10 mm, a width of 6-12 mm, and a thickness of 0.5-1 mm;
• the resonant cavity comprises an input cavity mirror and an output cavity mirror;
• the input cavity mirror and the output cavity mirror are respectively coated with a dielectric film for suppressing a starting laser oscillation in a band range of 1020 nm-1080 nm and realizing a starting laser oscillation in a band range of 1120 nm-1200 nm;
• the self-frequency-doubling crystal is cut into a slab shape along a direction having a maximum effective nonlinear coefficient;
• the pumping source is a diode laser matrix configured to emit a pump light in a band of 880 nm-980 nm;
• pump lights emitted by the pumping source forms a rectangular spot through the focusing system and is focused on a light transmission face of the self-frequency-doubling crystal in said resonant cavity;
• said self-frequency-doubling crystal is located at a focus of the focusing system, wherein the light transmission face of the self-frequency-doubling crystal is rectangular;
• and two large faces of the self-frequency-doubling crystal are each cooled by a heat sink, the light transmission direction of said self-frequency-doubling crystal is a phase matching direction of self-frequency doubling.