A laser medium unit 10 in a laser beam amplification device includes a plurality of laser media 14. A cooling medium flow path F1 is provided around the laser medium unit 10 to cool the laser medium unit 10 from outside. A sealed space between the laser media 14 is filled with gas or liquid, and a laser beam for passing through the sealed space is not interfered by a cooling medium flowing outside. Therefore, a fluctuation of an amplified laser beam is prevented, and a quality such as stability and focusing characteristics of the laser beam is improved.

A laser medium unit 10 in a laser beam amplification device includes a plurality of laser media 14. A cooling medium flow path F1 is provided around the laser medium unit 10 to cool the laser medium unit 10 from outside. A sealed space between the laser media 14 is filled with gas or liquid, and a laser beam for passing through the sealed space is not interfered by a cooling medium flowing outside. Therefore, a fluctuation of an amplified laser beam is prevented, and a quality such as stability and focusing characteristics of the laser beam is improved.

A system includes a master oscillator configured to generate a low-power optical beam. The system also includes a planar waveguide (PWG) amplifier configured to receive the low-power optical beam and generate a high-power optical beam having a power of at least about ten kilowatts. The PWG amplifier includes a single laser gain medium configured to generate the high-power optical beam. The single laser gain medium can reside within a single amplifier beamline of the system. The master oscillator and the PWG amplifier can be coupled to an optical bench assembly, and the optical bench assembly can include optics configured to route the low-power optical beam to the PWG amplifier and to route the high-power optical beam from the PWG amplifier. The PWG amplifier could include a cartridge that contains the single laser gain medium and a pumphead housing that retains the cartridge.

A laser amplifier device including an amplification element which includes a solid-state gain medium including a first main face and a second main face separated from each other by a distance which is smaller than the lateral dimensions. A heat spreader is thermally connected to, and substantially covering, the first main face. The heat spreader is optically transparent to a pump light and is in thermal contact with a heat sink. A first reflector substantially covers and faces the first main face and a second reflector substantially covers and faces the second main face; the reflectors being configured to reflect the pump light. The heat spreader and the first reflector are arranged such that the pump light passes through the heat spreader and through the first reflector and is reflected multiple times across the amplification element, between the first and second reflectors.

A laser amplifier device including an amplification element which includes a solid-state gain medium including a first main face and a second main face separated from each other by a distance which is smaller than the lateral dimensions. A heat spreader is thermally connected to, and substantially covering, the first main face. The heat spreader is optically transparent to a pump light and is in thermal contact with a heat sink. A first reflector substantially covers and faces the first main face and a second reflector substantially covers and faces the second main face; the reflectors being configured to reflect the pump light. The heat spreader and the first reflector are arranged such that the pump light passes through the heat spreader and through the first reflector and is reflected multiple times across the amplification element, between the first and second reflectors.

A laser apparatus that can generate a high-quality laser beam is provided. The laser apparatus is provided with a laser medium and an insulation layer. The laser medium has a first surface and a second surface. Incident laser light is incident on the first surface. The second surface totally reflects the incident laser light that is incident to the second surface at an incident angle equal to or larger than a critical angle. The insulation layer covers a second area of the second surface that surrounds a first area of the second surface, the first area totally reflecting the incident laser light. The laser medium is exposed in the first area.

A laser apparatus that can generate a high-quality laser beam is provided. The laser apparatus is provided with a laser medium and an insulation layer. The laser medium has a first surface and a second surface. Incident laser light is incident on the first surface. The second surface totally reflects the incident laser light that is incident to the second surface at an incident angle equal to or larger than a critical angle. The insulation layer covers a second area of the second surface that surrounds a first area of the second surface, the first area totally reflecting the incident laser light. The laser medium is exposed in the first area.

An actively cooled end-pumped solid-state laser gain device includes a bulk solid-state gain medium. An input-end of the gain medium receives a pump laser beam incident thereon and propagating in the direction toward an opposite output-end. The metal foil is disposed over a face of the gain medium extending between the input- and output-ends. A housing cooperates with the metal foil to form a coolant channel on the face the gain medium. The coolant channel has an inlet and an outlet configured to conduct a flow of coolant along the metal foil from the input-end towards the output-end. The metal foil is secured between the gain medium and portions of the housing running adjacent to the coolant channel. The metal foil provides a reliable thermal contact and imparts little or no stress on the bulk gain medium.

An actively cooled end-pumped solid-state laser gain device includes a bulk solid-state gain medium. An input-end of the gain medium receives a pump laser beam incident thereon and propagating in the direction toward an opposite output-end. The metal foil is disposed over a face of the gain medium extending between the input- and output-ends. A housing cooperates with the metal foil to form a coolant channel on the face the gain medium. The coolant channel has an inlet and an outlet configured to conduct a flow of coolant along the metal foil from the input-end towards the output-end. The metal foil is secured between the gain medium and portions of the housing running adjacent to the coolant channel. The metal foil provides a reliable thermal contact and imparts little or no stress on the bulk gain medium.

A laser system includes a laser diode that, upon activation, selectively produces a continuous wave of laser light or uniformly spaced, intermittent pulses of laser light. The system further includes a laser focuser with a plurality of lenses that focus the laser light produces by the laser diode and direct the laser light to an optical resonator. The optical resonator includes a lasing medium that, when intersected by the laser light from the laser diode, produces a beam of laser light with a wavelength that may be used for therapeutic treatment. The system is operable to produce the therapeutic laser light when the laser diode is operating in either the continuous wave mode or the pulsed mode, without moving components of the system relative to one another.