A power laser has a cavity (2) delimited at its opposite ends by a first partially transmitting window (3) and a second reflecting window ( 4). The first window (3) is constituted by at least one diamond wafer (5) with uncoated flat parallel surfaces, having a controlled thickness whose variations do not exceed 0.2 micron. The diamond wafer (5; 6) is mounted in an annular support (9; 10) of material which is a good heat conductor and is provided with a cooler (11; 12). The window (3) can comprise two parallel wafers (5.sub.A, 5.sub.B) of diamond separated by a calibrated distance (14) which is an uneven multiple of .lambda./4n, .lambda. being the laser wavelength and n the index of refraction of the medium between the wafers. Or the second window (4) can also be constituted by a diamond wafer (6) with a reflective metallic coating (60). A sweeping gas can be blown over the internal surface of at least one of the windows.
The invention concerns a composite diamond window (10) which includes a CVD diamond window pane (12) which is mounted to a CVD diamond window frame (14). The frame (14) is thicker than the pane (12) and has a radiation transmission aperature (16) therein across which the pane spans.
An attenuating device for attenuating optical power of a light beam, comprises an at least partly absorbing element adapted to receive and attenuate the optical power of the light beam, and a supporting element for supporting on at least one side the at least partly absorbing element. The at least partly absorbing element comprises at least one layer coated or evaporated on the supporting element with an increasing, decreasing, or varying thickness. The supporting element is provided with a material having a crystalline structure to provide compensation to a local heating in the at least partly absorbing element resulting from absorption of the light beam.
An ultraviolet range laser comprising a vacuum vessel having an open end portion hermetically sealed with an output mirror glass substrate, which is featured in that the output mirror glass substrate is formed of a glass material which is capable of allowing a laser beam of 337 nm in wavelength to pass therethrough at a transmittance of 80 to 96% as measured when the thickness of the glass substrate is set to 5 mm and whose thermal expansion coefficient falls in the range of 44.times.10.sup.-7 /.degree.C. to 55.times.10.sup.-7 /.degree.C. at a temperature of 0.degree. C. to 300.degree. C., and in that a metallic sealing ring is hermetically attached to the open end portion of vacuum vessel and the hermetical sealing of the open end portion of vacuum vessel with the output mirror glass substrate is achieved by hermetically adhering the output mirror glass substrate onto the metallic sealing ring via a low melting point solder glass interposed therebetween.
A high power solid state laser has a solid state laser medium with two ends and a longitudinal axis, at least one laser diode configured to end pump the laser medium, a resonator in optical alignment with the laser medium, a transparent and thermally conductive end cap disposed at each end of the laser medium and in thermal communication therewith, and at least one heat sink in thermal communication with the end caps. The end caps and the heat sink(s) cooperate to effect heat flow from the laser medium such that a substantial component of the heat flow is along the longitudinal axis of the laser medium, thus mitigating undesirable transverse temperature gradients within the laser medium and enhancing average power output therefrom.
A device is disclosed for delivering laser radiation to a target. The device includes an elongated, hollow, tubular member having an input end and a delivery end. A window is mounted near the delivery end of the device. The window provides a seal preventing smoke and debris from contaminating the interior of the device. In the preferred embodiment, the window is formed from a crystalline material, such as diamond, which has low absorption level for laser light and excellent thermal characteristics. In addition, the thickness of the window is selected to reduce reflection losses and increase the transmission level through the window without the need for fragile antireflection coatings.
