3d Systems, Inc.

Xingkun Wu

Jouni P Partanen

William F Hug

Hamid Hemmati

Gary Lee Reynolds

Nansheng Tang

Solid state lasers that use non-linear optical crystals to generate frequency tripled or quadrupled output in the ultraviolet have low lifetimes due to damage to the face of the non-linear crystal through which the ultraviolet signal exits. To prevent this damage, the tripling or quadrupling crystal is provided within a controlled environment that is maintained substantially free from contaminants such as silicon-bearing and organic compounds. The tripling or quadrupling crystal is enclosed within a tubular chamber with windows on the ends of the tube that provide optical access to the entrance and exit faces of the tripling or quadrupling crystal. All heating elements and alignment elements for the crystal are outside of the chamber. Because the crystal is stored within the hermetically sealed chamber, contaminants are not available within the environment of the crystal that could interact with the energetic photons of the ultraviolet output of the frequency multiplied solid state laser. The windows and walls of the chamber are preferably made of materials that can be cleaned effectively, such as sapphire or quartz for the windows and stainless steel for the walls and flanges of the chamber.

Extended lifetime frequency conversion crystals

An illumination system includes optics capable of adjusting the size of a beam of light and adjusting the focus of the beam of light. Spot size control optics adjusts the overall size of the beam of light and separately adjusts the ellipticity of the beam, primarily in one dimension. Light from the spot size control optics passes to focus control optics that control the overall focus of the beam of light and adjust the astigmatism of the beam by altering the focus position of the beam of light in one dimension. The laser system, the spot size control optics and the focus control optics are within an enclosure. Actuators under remote control from outside of the enclosure adjust both of the spot size control optics and focus control optics in the thermal environment of the illumination system.

Electronic spot light control

A solid state laser includes a high absorption coefficient solid state gain medium such as Nd:YVO that is side pumped with a semiconductor laser diode array. The resonant cavity of the solid state laser is positioned so that the TEM mode is spaced from the face of the laser through which the laser is pumped by a distance sufficient to reduce diffraction losses but sufficiently near to allow coupling of pump light into the gain mode. The gain medium, the doping level of the gain medium, and the operating temperature of the pump laser are selected to efficiently couple pump light into the gain mode. The pump laser is positioned to side pump the gain medium without collimating or focusing optics between the pump laser and the face of the gain medium. A gap between the pump laser and the gain medium is empirically selected to match the angular extent of the pump laser output light to the height of the gain mode at the position of the gain mode fixed to optimize coupling and diffraction losses.

Laser with absorption optimized pumping of a gain medium

A solid-state laser includes a high-absorption coefficient solid-state gain medium such as Nd:YVO.sub.4 that is side pumped with a semiconductor laser diode array. The resonant cavity of the solid-state laser is positioned so that the TEM.sub.00 mode is spaced from the face of the laser through which the laser is pumped by a distance sufficient to reduce diffraction losses but sufficiently near to allow coupling of pump light into the gain mode. The gain medium, the doping level of the gain medium, and the operating temperature of the pump laser are selected to efficiently couple pump light into the gain mode. The pump laser is positioned to side pump the gain medium without collimating or focusing optics between the pump laser and the face of the gain medium. A gap between the pump laser and the gain medium is empirically selected to match the angular extent of the pump laser output light to the height of the gain mode at the position of the gain mode fixed to optimize coupling and diffraction losses.

Growing community of inventors

Valencia, CA, United States of America

Xingkun Wu