1401results about How to "High beam quality" patented technology

A method for photoselective vaporization of prostate tissue includes delivering laser radiation to the treatment area on the tissue, via an optical fiber for example, wherein the laser radiation has a wavelength and irradiance in the treatment area on the surface of the tissue sufficient because vaporization of a substantially greater volume of tissue than a volume of residual coagulated tissue caused by the laser radiation. The laser radiation is generated using a neodymium doped solid-state laser, including optics producing a second or higher harmonic output with greater than 60 watts average output power. The delivered laser radiation has a wavelength for example in a range of about 200 nm to about 650 nm, and has an average irradiance in the treatment area greater than about 10 kilowatts / cm2, in a spot size of at least 0.05 mm2.

An apparatus and that provide an optical-fiber amplifier having at least one erbium-doped fiber section and an optical pump coupled to the erbium-doped fiber section, wherein the apparatus is operable to amplify signal pulses to high energy in the erbium-doped fiber section, the pulses having a wavelength in the range of about 1565 nm to about 1630 nm. In some embodiments, the amplifying fiber is ytterbium free.

A method for increasing the resolution when forming a three-dimensional article through successive fusion of parts of a powder bed, said method comprising providing a vacuum chamber, providing an electron gun, providing a first powder layer on a work table inside said vacuum chamber, directing an electron beam from said electron gun over said work table causing the powder layer to fuse in selected locations to form a first cross section of said three-dimensional article, providing a second powder layer on said work table, directing the electron beam over said work table causing said second powder layer to fuse in selected locations to form a second cross section of said three-dimensional article, reducing the pressure in the vacuum chamber from a first pressure level to a second pressure level between the providing of said first powder layer and said second powder layer.

An improved optical fiber comprising a waveguide with an input for coupling focused laser energy into the waveguide and communicating electromagnetic radiation in a propagation direction to an internally reflective tip of the waveguide, a tissue contacting surface wherein the light path from the reflecting surface to the transmitting surface in substantially homogenous in refractive index and cooled by fluid flow. In minimizing the variations in refractive index within the lateral light path, while providing active cooling directly below the tissue contact surface, the invention prevents internal reflections and beam distortion and greatly improves the efficiency and durability of the laterally directing probe. Free rotation of the tissue contact surface, about the lateral tip, may be provided and tissue vaporization efficiency may be improved by providing a morcellating tool on the tissue contact surface.

The present invention provides long life optics for a modular, high repetition rate, ultraviolet gas discharge laser systems producing a high repetition rate high power output beam. The invention includes solutions to a surface damage problem discovered by Applicants on CaF2 optics located in high pulse intensity sections of the output beam of prototype laser systems. Embodiments include an enclosed and purged beam path with beam pointing control for beam delivery of billions of output laser pulses. Optical components and modules described herein are capable of controlling ultraviolet laser output pulses with wavelength less than 200 nm with average output pulse intensities greater than 1.75×106 Watts / cm2 and with peak intensity or greater 3.5×106 Watts / cm2 for many billions of pulses as compared to prior art components and modules which failed after only a few minutes in these pulse intensities. Techniques and components are disclosed for minimizing the potential for optical damage and for reducing the pulse energy density to less than 100×10−6 J / cm3. Important improvements described in this specification have been grouped into the following subject matter categories: (1) Solution to CaF2 surface damage discovered by Applicants, (2) description of a high power ArF MOPA laser system, (3) description of beam delivery units, (4) polarization considerations (5) a high speed water-cooled auto shutter energy detector module and (6) other improvements.

The specification describes an optical fiber device wherein a LOM is converted to an HOM prior to entering the gain section. The gain section is a few mode fiber that supports the HOM. The output from the gain section, i.e. the HOM, may be utilized as is, or converted back to the LOM. With suitable design of the few mode fiber in the gain section of the device, the effective area, Aeff, may be greater than 1600 μm2. The large mode separation in the gain section reduces mode coupling, allowing greater design freedom and reducing the bend sensitivity of the optical fiber.

A miniaturized laser package is provided comprising a standard semiconductor laser package modified to accept a solid state microchip assembly pumped by the diode laser. Standard packages described in the invention include TO and HHL packages all of which are characterized by small dimensions, well sealed housing, robust mounting features, known characterized materials and economical production and assembly techniques characteristic of the semiconductor processing industry. In particular, the microchip lasers are produced using high density techniques that lend themselves to mass production, resulting in very low unit costs. At the same time, the compact laser devices provide a solution to the problem of providing laser radiation at high beam quality and good reliability features with a variety of wavelengths and operational characteristics and low noise features not available from diode lasers yet relying primarily on standardized designs, materials and techniques common to diode laser manufacturing. The devices constructed according to methods taught by the invention can therefore be readily integrated into numerous applications where power, reliability and performance are at a premium but low cost is essential, eventually replacing diode lasers in many existing systems but also enabling many new commercial, biomedical, scientific and military systems.

A semiconductor laser device including a laser element stack array emitting a two-dimensional array shaped group of laser beams consisting of rows of laser beams arranged linearly in parallel in a broken line configuration and optical elements arranged in front of the array, receiving rows of laser beams bent and collimated in a direction substantially perpendicular to the orientation of the broken line configuration. Laser beams are emitted from emitters or groups of emitters and are rotated by right angles so as to convert the laser beams to a plurality of rows aligned in parallel in an approximate ladder rung configuration and the distance between center axes of the rows of laser beams is shortened to condense the laser beams by converting them to a group of laser beams emitted from a common object and thereby making all laser beams converge to a single image.

A planar laser gain medium and laser system. The novel laser gain medium includes an active core having a high aspect ratio cross-section with a fast-axis dimension and a slow-axis dimension, signal claddings adapted to form reflective boundaries at fast-axis boundaries of the core, and a material adapted to minimize reflections at slow-axis boundaries of the core. In an illustrative embodiment, the laser gain medium is an optical fiber. The core and claddings form a waveguide adapted to control modes propagating in the fast-axis direction. When the laser gain medium is employed as a laser oscillator, a high reflectivity mirror and an outcoupler are positioned at opposite ends of the core to form a laser resonator adapted to control modes in the slow-axis direction.

The present invention relates to a beam reshaping device for a plane array semiconductor laser. The device includes a fast axis collimating lens, a slow axis collimating lens, a ladder lens, a first parallelepiped prism unit, and a second parallelepiped prism unit. The beam emitted by the plane array semiconductor laser passes through the fast axis collimating lens and the slow axis collimating lens, and lowers the divergence angle of the fast axis and the divergence angle of the slow axis. The irradiance interspace between bars can be eliminated by the ladder lens and can be compressed in the direction of the fast axis. Finally, part of beam can be moved parallel along the fast axis direction by the first parallelepiped prism unit and the second parallelepiped prism unit, and then be moved along the slow axis direction. Through the above process, the beam is realigned, and the purpose that the quality of the fast axis beam and the quality of the slow axis beam tend to be coincident is reached. The realigned beam can get high-power high-brightness facula after being focused. The optical apparatus used in the present invention is easy to be produced and convenient to be adjusted with simple structure.

This invention relates to an optical fibre that comprises a core (4) of lower refractive index that is surrounded by a cladding which includes regions of a higher refractive index and is substantially periodic, where the core (4) has a longest transverse dimension that is longer than a single, shortest period of the cladding. In a fibre of this type light is substantially confined to the core area by virtue of the photonic band gap of the cladding material. The invention also relates to a method of manufacturing such an optical fibre, comprising the steps of forming a stack of canes (5), the stack (5) including at least one truncated cane (6) that defines an aperture (7), and then drawing the stack (5) into a fibre having an elongate cavity. The fibre is suitable for high power uses, but is equally suitable for other areas, e.g. optical amplifiers, spectral filters, lasers, gas sensors and telecommunications networks.

A method for effective injection seeding is based on continuous wavelength sweeping for matching the injected seeds with one or more longitudinal mode(s) of the slave oscillator in every pulse. This is achieved through rapidly varying laser drive current, as a result of RF modulation. Depending on the modulation parameters, the seeder may be operated in CW or quasi-CW or pulsed mode, with a narrow or broad bandwidth, for injection seeding of single longitudinal mode or multimode. The wavelength and bandwidth of the laser output can be tuned according to the needs. Injection seeding of high repetition rates is achievable. From pulse to pulse, the master-slave resonance persists though may occur at different longitudinal modes upon cavity length fluctuations. Cavity length control and phase locking schemes are consequently not required. The present invention also encompasses an injection seeding laser system, which is constructed in accordance with the inventive method, and a novel application of RF modulated laser diode to spectrum / wavelength control and to producing high power Gaussian beam with narrow pulse width in a stable, reliable, and cost-effective manner.

Several methods are disclosed for the generation of coherent short-wavelength electromagnetic radiation through optical nonlinear frequency mixing means. The invention involves several stages of efficient nonlinear frequency conversion to shift the output of high-power infra-red fiber-lasers into the vacuum ultraviolet (VUV). The described laser source architecture is designed around non-critically phase-matched (NCPM) sum-frequency mixing (SFM) interactions in the nonlinear crystal CLBO. The NCPM interaction is an optimum condition for bulk frequency conversion of cw radiation because it allows tight focusing of the input laser radiation without Poynting vector walk-off, thereby increasing the non-linear drive significantly. The sub-200-nm output wave is generated from SFM of a long-wave IR laser field and a short-wave UV laser field. The long-wave laser beam may be derived directly from a rare-earth-doped fiber laser, whereas the short-wavelength UV beam is provided as the fourth frequency harmonic of a second rare-earth-doped fiber laser system.

An improved optical fiber comprising a waveguide with an input for coupling focused laser energy into the waveguide and communicating electromagnetic radiation in a propagation direction to an internally reflective tip of the waveguide, a tissue contacting surface wherein the light path from the reflecting surface to the transmitting surface in substantially homogenous in refractive index and cooled by fluid flow. In minimizing the variations in refractive index within the lateral light path, while providing active cooling directly below the tissue contact surface, the invention prevents internal reflections and beam distortion and greatly improves the efficiency and durability of the laterally directing probe. Free rotation of the tissue contact surface, about the lateral tip, may be provided and tissue vaporization efficiency may be improved by providing a morcellating tool on the tissue contact surface.

Laser modules using two-dimensional laser diode arrays are combined to provide an intense laser beam. The laser diodes in a two-dimensional array are formed into rows and columns, and an optical assembly images light generated by laser diodes in a column into an optical fiber. The laser light outputs of the laser modules are combined by a spectral combiner into an optical fiber to form an intense laser beam.

A tunable highly efficient and high power ultraviolet (UV) laser source with good spatial beam quality is disclosed. A plurality of laser lights are generated by ytterbium (Yb) doped fiber laser and erbium / ytterbium (Er / Yb) doped fiber laser. In order to achieve a desired UV wavelength, the Yb-doped and Er / Yb-doped fiber lasers are tuned to generate laser lights of certain wavelengths based on a desired UV light wavelength. The laser lights from the Er / Yb-doped fiber laser and the Yb-doped fiber laser are frequency-doubled. The frequency-doubled laser lights are non-linearly frequency-mixed to generate a UV light with the desired wavelength.

Described are laser systems for treating skin. The system includes a first solid-state laser for producing a first output beam, a second solid state laser for producing a second output beam, and a delivery device for directing the second output beam to a target region of skin. The second solid state is adapted to absorb a first part of the first output beam for generating excitation in a rare-earth doped gain medium to produce the second output beam. The second output beam is for treating the skin.

The invention discloses a polarization beam-combination device for a pulsed laser. The polarization beam-combination device comprises the pulsed laser, an input beam splitter, n laser amplifiers and n-1 polarization coherent beam-combination units. The pulsed laser outputs a beam of seed light. The input beam splitter divides the seed light into n sub-seed light beams. The n laser amplifiers respectively carry out power amplification to the n sub-seed light beams. The n-1 polarization coherent beam-combination units carry out pairwise polarization in-phase beam-combination for n-1 times to n laser beams output by the n laser amplifiers. N is a natural number which is bigger than or equal to two. An output end of the polarization beam-combination device is connected with an output beam splitter. A hard light output end of the output beam splitter is used as an output end of the polarization coherent beam-combination units. Light output from a low light output end of the output beam splitter shoots into a relative phase detection module of a drive phase control module, and the relative phase detection module enables phase positions of two laser beams to be consistent. Through adoption of a polarization detection method, the polarization beam-combination device detects the relative phase positions of the two laser beams, and is capable of achieving coaxial combination of a plurality of coherent light beams, high in combined efficiency and good in beam quality.

The invention relates to optical fiber and a manufacture method thereof, in particular to large-mode active optical fiber and a manufacture method thereof. The large-mode active optical fiber is formed by drawing a fiber core and a quartz glass inner cladding, a quartz glass outer cladding and a coating which are sequentially coated on the outer surface of the fiber core, wherein the fiber core is formed by depositing, melting and collapsing silicon tetrachloride doped with rare-earth ions in a quartz glass tube; the refractive index of the fiber core is a gradually changed refractive index, and a fiber core refractive index section parameter alpha is not smaller than 1 and not larger than 3; and the appearance of the quartz glass inner cladding is in a regular gengon shape. The large-mode active optical fiber has the advantages of large mode and similar single-mode output, improves the capacity of bearing laser power and the energy storage density of the active optical fiber, improves the light beam quality of output laser, solves the problem of hollow ring of the output laser, greatly improves the reliability of high-power optical fiber laser devices and the utilization rate of raw materials and reduces the manufacture cost.

The present invention provides a control system for a modular high repetition rate two discharge chamber ultraviolet gas discharge laser. In preferred embodiments, the laser is a production line machine with a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber.Novel control features specially adapted for a two-chamber gas discharge laser system include: (1) pulse energy controls, with nanosecond timing precision (2) precision pulse to pulse wavelength controls with high speed and extreme speed wavelength tuning (3) fast response gas temperature control and (4) F2 injection controls with novel learning algorithm.

The invention relates to non-linear optical frequency conversion and the application of the non-linear optical frequency conversion and provides a method and a device which can widen the preparation requirements for a biological sample, do not need preparation of the sample, are high in measurement sensitivity, and can achieve high resolution, fast and real-time biological sample moisture content and distribution imaging measurement. The technical scheme is that the biological tissue moisture measurement device based on terahertz wave attenuated total reflectance (ATR) is composed of a tunable terahertz (THz) radiation source, a non-spherical face lens assembly, a total reflection prism, a two-dimensional mobile scanning platform, a terahertz wave detector and a computer. The total reflection prism is placed in the middle of the non-spherical face lens assembly, the face to be tested of a biological sample to be tested clings to the top face of the total reflection prism fixed on the two-dimensional mobile scanning platform, terahertz (THz) waves are projected to the terahertz detector through the non-spherical face lens assembly, and a detection result of the terahertz detector is output to the computer. The biological tissue moisture measurement device and the method based on the terahertz wave attenuated total reflectance (ATR) are mainly used for biological sample moisture content and distribution imaging measurement.

The invention discloses a micro-embedded self-lubricating texture on the surfaces of a gear and a cam and a preparation method thereof. The preparation method comprises the following steps of: performing micro texture processing on the surfaces of the gear and the cam by an Nd: YAG laser processing technology; and embedding a solid lubricant into the micro texture on the surfaces of the gear and the cam by a molding bonding technology of a self-lubricating composite material. The self-lubricating composite material comprises the following formula components in percentage by mass: 15 to 85 percent of polyimide (PI), 0 to 85 percent of polytetrafluoroethylene (PTFE), 10 to 40 percent of MoS2, 0 to 15 percent of WS2, 0 to 16 percent of graphite fluoride, 5 to 15 percent of graphite, 0 to 12 percent of PbO, 0 to 6 percent of antimony trioxide, 0 to 10 percent of CaF2 or BaF2, 0 to 15 percent of hexagonal boron nitride, 0 to 15 percent of nano lubricant and 0 to 5 percent of additive. According to the micro-embedded self-lubricating texture, the self-lubricating texture is subjected to micro embedding on the surfaces of the gear and the cam to ensure that the solid lubricant on the friction surface is stably supplied and uniformly coated, so that the lubrication and anti-wear properties of friction pairs such as the gear and the cam under complicated and harsh operating conditions are improved.

The invention discloses a video disc fixing laser. A video disc laser crystal and a laser cavity resonator output lens form a laser cavity resonator; the focus of one of two paraboloid reflectors positioned in a conjugating way is positioned in the video disc laser crystal; a pump light sent by a semiconductor laser stack array is firstly collimated by a pump light collimator, then is imaged on the video disc laser crystal through the two paraboloid reflectors and is output as laser formed through the laser cavity resonator at last. The invention adopts the method of semiconductor stack array and has high efficiency, long service life and convenient equipment maintenance. A double-paraboloid pump system positioned in the conjugating way reduces the requirement for the collimation degree of the pump light and realizes high-efficiency imaging of the pump light. Each secondary pump luminous spot has regular and symmetrical shape, reasonable power density distribution and small position excursion of the light luminous spots for each imaging, and high-efficiency and even pumping is realized. The equipment has smaller volume, simple mechanical structure and adjustment and lighter weight, and is convenient for industrial application.

The present invention provides a control system for a modular high repetition rate two discharge chamber ultraviolet gas discharge laser. In preferred embodiments, the laser is a production line machine with a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. Novel control features specially adapted for a two-chamber gas discharge laser system include: (1) pulse energy controls, with nanosecond timing precision (2) precision pulse to pulse wavelength controls with high speed and extreme speed wavelength tuning (3) fast response gas temperature control and (4) F2 injection controls with novel learning algorithm.

A compact high energy photoelectron injector integrates the photocathode directly into a multicell linear accelerator with no drift space between the injection and the linac. High electron beam brightness is achieved by accelerating a tightly focused electron beam in an integrated, multi-cell, X-band rf linear accelerator (linac). The photoelectron linac employs a Plane-Wave-Transformer (PWT) design which provides strong cell-to-cell coupling, easing manufacturing tolerances and costs.

The invention relates to a Bragg refractive waveguide edge transmitting semiconductor laser with a low horizontal divergence angle, wherein the P electrode of the laser is placed on the top face of a cover layer and is electrically connected onto the cover layer; the N electrode is positioned on the back face of a substrate and is electrically connected to the substrate; a center cavity is positioned between an upper waveguide layer and a lower waveguide layer; an active area is inserted in the center cavity; a Bragg refractive waveguide formed by periodically distributing a plurality of layers of N-doped materials with a high refractive index and a low refractive index is adopted in the lower waveguide layer on; and a Bragg refractive waveguide formed by periodically distributing a plurality of layers of P-doped materials with a high refractive index and a low refractive index is adopted in the upper waveguide layer. The Bragg refractive waveguide edge transmitting semiconductor laser with the low horizontal divergence angle has the advantages that: effects such as catastrophic damage, hole burning, electric heat overburning, beam filamentization and the like on the end face of the traditional edge transmitting semiconductor laser can be effectively improved, and the laser can realize the large mode-volume and stable single-transverse-mode work because of the great gain loss difference between a basic mode and a high-order mode, the full wave at half maximum (FWHM) of the transverse far-field divergence angle of the laser can reach below 10 DEG.