Face-cooled laser device having increased energy storage and output
AssigneeGeneral Electric Company
InventorJoseph P. Chernoch
Life of this patent
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Abstract
A solid laser rod optically pumped is cooled to produce a large thermal gradient extending only along the radiation propagation direction. This thermal gradient results in a reduced average gain cross section, permitting increased energy storage and correspondingly increased laser energy output without thermal optic distortion. In Nd:YAG lasers, a longitudinal cooling profile allows super-radiance at the high gain 1.06 .mu.m transition to be suppressed and useful laser operation to be obtained on lower gain transitions, notably at 0.94 .mu.m or 1.32 .mu.m may be obtained.
Claims27
A face-cooled solid rod laser comprising:
- a pair of aligned mirrors defining an optical resonant cavity therebetween;
- a rod of optically active laser material disposed within said cavity and optically aligned with said mirrors and adapted, when irradiated with optical pumping radiation, to emit coherent radiation at a predetermined optical wavelength, said rod having a longitudinal axis and opposite end faces that are substantially parallel so as to permit passage of radiation along said axis;
- means for optically pumping said rod situated alongside at least a portion of the longitudinal surface of said rod;
- and
- means for maintaining said end faces at a predetermined temperature differential to establish a thermal gradient parallel to said longitudinal axis.
A method of increasing energy output of a rod laser having opposite end faces that are substantially parallel to each other so as to permit passage of radiation along the longitudinal axis of said rod, comprising:
- irradiating the rod of said laser with pumping radiation through the longitudinal surface of said rod to produce a beam of coherent electromagnetic radiation oscillating through said rod between mirrors aligned with said axis of said rod;
- and
- maintaining a predetermined temperature differential along the length of said rod parallel to said longitudinal axis.
A total internal reflection face pumped laser comprising:
- an elongated homogeneous body of an active laser medium disposed within a laser cavity defined by two mirrors, said body having a longitudinal axis and at least two optically plane faces extending substantially parallel to each other and to said longitudinal axis;
- pumping means for impinging electromagnetic radiation upon at least one of said optically plane faces to excite atoms of said body to a metastable state thereby producing a population inversion therein;
- means for passing fluid coolant across at least one of said optically plane faces to maintain said faces at a predetermined temperature differential to produce a thermal gradient through said body from one of said faces to the other;
- and
- means for passing a beam of electromagnetic radiation through said pumped body in an off-axial direction at an angle of incidence relative to said optically plane faces of said body sufficient to produce a plurality of total internal reflections by each of said optically plane faces of said body, said mirrors being aligned generally perpendicular to said beam so that individual rays of said electromagnetic radiation pass through said body a plurality of times.
A method of increasing energy output of a total internal reflection face pumped laser having an elongated homogeneous body of an active laser medium, said body having a longitudinal axis and at least two optically plane faces extending substantially parallel to each other and to said longitudinal axis comprising:
- irradiating the body with pumping radiation through said optically plane faces to produce a beam of coherent electromagnetic radiation oscillating between mirrors aligned with said beam such that said radiation is reflected through said body a plurality of times;
- said beam reflecting from each of said optically plane faces a plurality of times during each passage thereof through said body;
- and
- maintaining one of said optically plane faces at a first predetermined temperature such that the other of said optically plane faces is at a temperature substantially different from said predetermined temperature.
Dependencies are inferred from the claim text.