Abstract: A laser resonator comprises a cylindrical gain medium, a cooling system and a coupling member. The cylindrical gain medium comprises a central axis, an outer side surface, two opposing end faces and a first depression in the outer side surface. The cooling system comprises a cooling jacket disposed around the gain medium that defines a cooling cavity, in which cooling fluid is guided over the side surface of the gain medium. In one embodiment, the cooling jacket comprises a second depression. The coupling member is received within the first and second depressions. Movement of the first depression along the central axis relative to the cooling jacket is restricted by the coupling member.

Abstract: In a method of stabilizing pump energy, a gain medium is provided having an absorption coefficient that varies with wavelength. An absorption coefficient curve of the absorption coefficient or a range of wavelengths comprises peaks and valleys. Pump energy is generated at an operating wavelength within one of the valleys, at which the absorption coefficient is approximately at a minimum. The pump energy is transmitted through the gain medium. A portion of the pump energy is absorbed with the gain medium and laser light is emitted from the gain medium responsive to the absorbed pump energy. The non-absorbed pump energy (feedback pump energy) is fed back to the pump module. The operating wavelength of the pump energy is stabilized using the feedback pump energy.

Abstract: In a method of stabilizing pump energy, a gain medium is provided having an absorption coefficient that varies with wavelength. An absorption coefficient curve of the absorption coefficient or a range of wavelengths comprises peaks and valleys. Pump energy is generated at an operating wavelength within one of the valleys, at which the absorption coefficient is approximately at a minimum. The pump energy is transmitted through the gain medium. A portion of the pump energy is absorbed with the gain medium and laser light is emitted from the gain medium responsive to the absorbed pump energy. The non-absorbed pump energy (feedback pump energy) is fed back to the pump module. The operating wavelength of the pump energy is stabilized using the feedback pump energy.

Abstract: In a method, a gain medium is provided having an absorption coefficient that varies with wavelength. An absorption coefficient curve of the absorption coefficient or a range of wavelengths comprises peaks and valleys. A pump module is operated to output pump energy at an operating wavelength within one of the valleys, at which the absorption coefficient is approximately less than 40% of the absorption coefficient at an adjacent peak of the absorption coefficient curve defining the valley. The pump energy is directed through the gain medium. A portion of the pump energy is absorbed with the gain medium and laser light is emitted from the gain medium responsive to the absorbed pump energy. The non-absorbed pump energy (feedback pump energy) is fed back to the pump module. The operating wavelength of the pump energy is stabilized using the feedback pump energy.

Abstract: A laser resonator comprises a cylindrical gain medium, a cooling system and a coupling member. The cylindrical gain medium comprises a central axis, an outer side surface, two opposing end faces and a first depression in the outer side surface. The cooling system comprises a cooling jacket disposed around the gain medium that defines a cooling cavity, in which cooling fluid is guided over the side surface of the gain medium. In one embodiment, the cooling jacket comprises a second depression. The coupling member is received within the first and second depressions. Movement of the first depression along the central axis relative to the cooling jacket is restricted by the coupling member.

Abstract: In a method, a gain medium is provided having an absorption coefficient that varies with wavelength. An absorption coefficient curve of the absorption coefficient or a range of wavelengths comprises peaks and valleys. A pump module is operated to output pump energy at an operating wavelength within one of the valleys, at which the absorption coefficient is approximately less than 40% of the absorption coefficient at an adjacent peak of the absorption to coefficient curve defining the valley. The pump energy is directed through the gain medium. A portion of the pump energy is absorbed with the gain medium and laser light is emitted from the gain medium responsive to the absorbed pump energy. The non-absorbed pump energy (feedback pump energy) is fed back to the pump module. The operating wavelength of the pump energy is stabilized using the feedback pump energy.

Abstract: A method for optically pumping a gain-medium with partially polarized or unpolarized pump-light having a wavelength at which that gain-medium has an absorption that is dependent on the polarization plane of the pump-light is disclosed. The pump-light is directed into the gain-medium. The strongest-absorbed polarization component of the pump-light is substantially absorbed and the weakest-absorbed polarization component is partially transmitted by the gain-medium. The polarization plane of the transmitted component is rotated through 90 degrees and the polarization-rotated pump-light is directed back into the gain-medium, wherein it is substantially absorbed.

Abstract: A method for optically pumping a gain-medium with partially polarized or unpolarized pump-light having a wavelength at which that gain-medium has an absorption that is dependent on the polarization plane of the pump-light is disclosed. The pump-light is directed into the gain-medium. The strongest-absorbed polarization component of the pump-light is substantially absorbed and the weakest-absorbed polarization component is partially transmitted by the gain-medium. The polarization plane of the transmitted component is rotated through 90 degrees and the polarization-rotated pump-light is directed back into the gain-medium, wherein it is substantially absorbed.

Abstract: An arrangement for monitoring the power delivered by a photon channeling element including an integrating chamber to receive an output end of the photon channeling element and an optical surface positioned to reflect a portion of the laser-light exiting the photon channeling element at substantially normal incidence to the beam centerline. The integrating chamber may be adapted to collect substantially all of the laser-light reflected from the optical surface. The arrangement may also include a sensor in optical contact with a portion of the integrating chamber that is out of the path of laser-light reflected from the optical surface.

Abstract: An arrangement for monitoring the power delivered by a photon channeling element including an integrating chamber to receive an output end of the photon channeling element and an optical surface positioned to reflect a portion of the laser-light exiting the photon channeling element at substantially normal incidence to the beam centerline. The integrating chamber may be adapted to collect substantially all of the laser-light reflected from the optical surface. The arrangement may also include a sensor in optical contact with a portion of the integrating chamber that is out of the path of laser-light reflected from the optical surface.

Abstract: A medical laser system is disclosed for ablating biological material. The system includes an Erbium:YAG gain medium capable of generating a pulsed output having a wavelength of 2.9 microns. The laser is optimized to generate a pulsed output having a repetition rate of at least 50 hertz and preferably at least 100 hertz. The output is delivered to the target tissue via an optical fiber. Preferably, a suction source is provided to aspirate the tissue as it is being ablated. The erbium laser system provides accurate ablation with minimal damage to surrounding tissue.

Abstract: A medical laser system is disclosed for ablating biological material. The system includes an Erbium:YAG gain medium capable of generating a pulsed output having a wavelength of 2.9 microns. The laser is optimized to generate a pulsed output having a repetition rate of at least 50 hertz and preferably at least 100 hertz. The output is delivered to the target tissue via an optical fiber. Preferably, a suction source is provided to aspirate the tissue as it is being ablated. The erbium laser system provides accurate ablation with minimal damage to surrounding tissue.

Abstract: A pulsed solid state laser system is disclosed which utilizes a plurality of individual laser rods which are sequentially pumped and whose beans are combined into a single interleaved output bean. The individual laser rods are pumped at an average power level which is below that for maximum output power from each rod, thereby obviating the need for refrigeration cooling. A compact optical system is disclosed which permits a constant beam size even at different pump levels and other advantages. A compact cooling system is also disclosed.

Abstract: A cylindrically shaped gain medium for a laser resonant cavity. The gain medium has an outer cylindrical side surface and two opposing end faces. An annular groove is formed in the side surface. An energy source excites the gain medium to create a laser beam inside the cavity. The laser beam passes longitudinally through the gain medium. The annular groove defines an annular aperture inside the gain medium for the laser beam. The annular aperture has a diameter that is smaller than a diameter of the side surface and the end faces.

Abstract: A gain medium assembly for a laser system that has or attaches to a cooling fluid source. The gain medium assembly includes a laser system gain medium, an insulating jacket disposed around the gain medium, a cooling jacket disposed around the insulating jacket, and an energy source for optically exciting and heating the gain medium. The cooling jacket defines a cooling channel between itself and the insulating jacket for guiding flowing cooling fluid from the cooling fluid source over the insulating jacket. During operation, the heat in the gain medium dissipates through the insulating jacket and to the cooling fluid in the cooling channel, while the gain medium is maintained at a temperature that is significantly higher than the temperature of the cooling fluid. A gap may be formed between the gain medium and the insulating jacket to allow some of the cooling water to fill the gap and form a thin layer of water, and to provide uniform heat conduction, between the gain medium and the insulating jacket.

Abstract: A liquid circulation system for cooling a laser head is disclosed. The circulation system comprises a main storage tank for holding a cooling liquid and a pump for circulating the liquid from the tank through the laser head and back into the tank. The cooling system includes a heat exchanger for cooling the liquid. The heat exchanger includes liquid carrying coils and an impeller fan rotatable about an axis. The fan being located adjacent the coils for drawing air across the coils in an axial direction with respect to the fan and for expelling the air radially with respect to the fan.

Abstract: A pulsed solid state laser system is disclosed which utilizes a plurality of individual laser rods which are sequentially pumped and whose beans are combined into a single interleaved output bean. The individual laser rods are pumped at an average power level which is below that for maximum output power from each rod, thereby obviating the need for refrigeration cooling. A compact optical system is disclosed which permits a constant beam size even at different pump levels and other advantages. A compact cooling system is also disclosed.

Abstract: A medical laser system is disclosed for ablating biological material. The system includes an Erbium:YAG gain medium capable of generating a pulsed output having a wavelength of 2.9 microns. The laser is optimized to generate a pulsed output having a repetition rate of at least 50 hertz and preferably at least 100 hertz. The output is delivered to the target tissue via an optical fiber. Preferably, a suction source is provided to aspirate the tissue as it is being ablated.

Abstract: A medical laser system is disclosed for ablating biological material. The system includes an Erbium:YAG gain medium capable of generating a pulsed output having a wavelength of 2.9 microns. The laser is optimized to generate a pulsed output having a repetition rate of at least 50 hertz and preferably at least 100 hertz. The output is delivered to the target tissue via an optical fiber. Preferably, a suction source is provided to aspirate the tissue as it is being ablated. The erbium laser system provides accurate ablation with minimal damage to surrounding tissue.

Abstract: A folded Q-switched laser cavity uses total internal reflections of prisms to fold the intracavity beam. The index of refraction and the orientation of the prisms are selected to induce a predetermined phase delay between the two orthogonal polarization components of the linearly polarized intracavity beam. The predetermined phase delay rotates the intracavity beam polarization to an orthogonal direction such that an intracavity polarizer rejects the beam and the laser is held off from lasing. An electro-optic Q-switch cell is intermittently turned "on" whereby a second predetermined phase delay is induced onto the intracavity beam. The combination of the two predetermined phase delays results in a beam polarization orientation that is not rejected by the polarizer and the laser is not held off from lasing.