초록 ▼

An optically pumped single mode laser, e.g. Nd:YAG crystal (20) with planoconcave mirrors is increased in efficiency by an order of magnitude to about 8% by optics (25, 27) for focusing the high power multimode output of laser diode arrays (21, 22) into the mode volume (20′) of the laser medium (20)

An optically pumped single mode laser, e.g. Nd:YAG crystal (20) with planoconcave mirrors is increased in efficiency by an order of magnitude to about 8% by optics (25, 27) for focusing the high power multimode output of laser diode arrays (21, 22) into the mode volume (20′) of the laser medium (20). A plurality of these optically pumped single mode lasers (1-4) may be cascaded in a ring with dichroci mirrors (M1-M4) at the corners for coupling in the laser diode arrays, each having its own means for spatially tailoring its beam to concentrate pump distribution inside the lasing mode volume of the medium. An InGaAlAs pump diode (30) with its wavelength of the same as a lasing medium makes the ring unidirectional. The questions raised in reexamination request No. 90/002,473, filed Oct. 10, 1991, have been considered and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1,570(e).

대표청구항 ▼

[An optically]A Laser diode pumped single mode laser comprising an optical resonator cavity, a laser medium in said resonator cavity, said laser medium having an optical axis and two ends, one end at each of two opposite sides of said medium intersected by said optical axis, an array of laser diode

[An optically]A Laser diode pumped single mode laser comprising an optical resonator cavity, a laser medium in said resonator cavity, said laser medium having an optical axis and two ends, one end at each of two opposite sides of said medium intersected by said optical axis, an array of laser diodes positioned for pumping said laser medium in the direction of the axis of said resonator cavity, said laser diode array being a source of light of poor spatial and spectral qualities and means for causing [the pump]distribution of the light from [said]the array of laser diodes to be concentrated inside [the]a lasing mode volume of said medium at an imput pump power of at least 100 milliwatts. [2. An optically pumped laser as defined in claim 1 wherein an array of laser diodes and said means for concentration is provided at both ends of said medium, and including a mirror for separating the output of said medium as an output beam from the pump distribution at one end of said medium.] [3. An optically pumped laser as defined in claim 2 including a second array of laser diodes at one end of said medium, and means for combining at said one end the output of the second array of laser diodes with the output of the first array of laser diodes for a combined pumping beam into said lasing mode volume through separate means for each array of laser diodes for concentration of the pump distribution form each of said array of laser diodes inside the lasing mode volume of said medium.] [4. An optically pumped laser as defined in claim 2 including a plurality of cascaded laser mediums arranged with separate mirrors to form a closed optical polygon for each laser medium, each laser medium having at least one laser diode array and means for concentration of pump distribution of light from the laser diode array into the lasing mode volume of the laser medium through one of said separate mirrors coupling said laser mediums in said polygon, an injection locking laser diode operating at the wavelength of said medium, and means for combining the output of said injection locking laser diode with the output of one array of laser diodes for pumping one of said mediums in a predetermined direction around said closed optical polygon, and means for extracting from said closed optical polygon output laser beam emanating from one medium in said predetermined direction.] [5. An optically pumped laser as defined in claim 2 including a plurality of cascaded laser mode volumes arranged in a zig-zag pattem with the optical axis of adjacent optical mode volumes intersecting at a corner of said zig-zag pattern, a mirror at each corner, each mode volume having at each end a laser diode array and means for concentration of light from said laser diode array into the mode volume for pumping and means at one end of said zig-zag pattern for extracting an output laser beam emanating from one laser mode volume.]