249 results about "Mid infrared laser" patented technology

A surgical technique for removing corneal tissue with scanned infrared radiation is disclosed which utilizes short mid-infrared laser pulses to provide a tissue removal mechanism based on photospallation. Photospallation is a photomechanical ablation mechanism which results from the absorption of incident radiation by the corneal tissue. Since photospallation is a mechanical ablation process, very little heat is generated in the unablated adjacent tissue. The disclosed surgical system includes a scanning beam delivery system which allows uniform irradiation of the treatment region and utilizes low energy outputs to achieve controlled tissue removal. A real-time servo-controlled dynamic eye tracker, based on a multiple-detector arrangement, is also disclosed which senses the motion of the eye and provides signals that are proportional to the errors in the lateral alignment of the eye relative to the axis of the laser beam. Temporal and frequency discrimination are preferably utilized to distinguish the tracking illumination from the ambient illumination and the surgical laser beam. A laser parametric generator for surgical applications is disclosed which utilizes short-pulse, mid-infrared radiation. The mid-infrared radiation may be produced by a pump laser source, such as a neodymium-doped laser, which is parametrically down converted in a suitable nonlinear crystal to the desired mid-infrared range. The short pulses reduce unwanted thermal effects and changes in adjacent tissue to potentially submicron-levels. The parametrically converted radiation source preferably produces pulse durations shorter than 25 ns at or near 3.0 microns but preferably close to the water absorption maximum associated with the tissue. The down-conversion to the desired mid-infrared wavelength is preferably produced by a nonlinear crystal such as KTP or its isomorphs. In one embodiment, a non-critically phased-matched crystal is utilized to shift the wavelength from a near-infrared laser source emitting at or around 880 to 900 nm to the desired 2.9-3.0 microns wavelength range. A fiber, fiber bundle or another waveguide means utilized to separate the pump laser from the optical parametric oscillation (OPO) cavity is also included as part of the invention.

This invention is an improved method and device for treating varicose veins 200 or the greater saphenous vein 202. The method comprises the use of infrared laser radiation in the region of 1.2 to 2.2 um in a manner from inside the vessel 200 or 202 such that the endothelial cells of the vessel wall 704 are damaged and collagen fibers in the vessel wall 704 are heated to the point where they permanently contract, the vessel 200 or 202 is occluded and ultimately resorbed. The device includes a laser 102 delivered via a fiber optic catheter 300 that may have frosted or diffusing fiber tips 308, or that may be provided with a protective spacer. A motorized pull back device 104 may be used, and a thermal sensor 600 may be used to help control the power required to maintain the proper treatment temperature.

A compact mid-IR laser device utilizes an external cavity to tune the laser. The external cavity may employ a Littrow or Littman cavity arrangement. In the Littrow cavity arrangement, a filter, such as a grating, is rotated to provide wavelength gain medium selectivity. In the Littman cavity arrangement, a reflector is rotated to provide tuning. A quantum cascade laser gain medium provides mid-IR frequencies suitable for use in molecular detection by signature absorption spectra. The compact nature of the device is obtained owing to an efficient heat transfer structure, the use of a small diameter aspheric lens for both the output lens and the external cavity lens and a monolithic assembly structure to hold the optical elements in a fixed position relative to one another. The compact housing size may be approximately 20 cm×20 cm×20 cm or less. Efficient heat transfer is achieved using a thermoelectric cooler TEC combined with a high thermal conductivity heat spreader onto which the quantum cascade laser gain medium is thermally coupled. The heat spreader not only serves to dissipate heat and conduct same to the TEC, but also serves as an optical platform to secure the optical elements within the housing in a fixed relationship relative on one another. The small diameter aspheric output and external cavity lens each may have a diameter of 10 mm or less and each lens is positioned to provided a collimated beam output from the quantum cascade laser gain medium. The housing is hermetically sealed to provide a rugged, light weight portable MIR laser source.

A laser system capable of efficient production of high energy sub-nanosecond pulses in the 2-15 μm spectral region is disclosed. Diode pumped solid state lasers are used as pump sources. The system design is simple, reliable and compact allowing for easy integration. The laser system includes a combination of compact solid-state ˜1 micron laser sources, producing high power picosecond pulses, with optical parametric amplification and a quasi-continuous wave laser for seeding the amplification process that enables the efficient conversion of the high power ˜1 micron laser radiation to tuneable mid-infrared sub-ns pulses. New parametric processes are presented for achieving high gains in bulk nonlinear crystals. Furthermore, a method of exceeding the fundamental conversion efficiency limit of direct three wave mixing is presented. The compact and robust nature of this novel laser system opens up the use of high power and high peak power mid-infrared laser pulses to a wide variety of important medical and dental applications.

The invention discloses a mid-infrared cascade Raman fiber lasers, which is characterized by comprising a doubly coated ZBLAN fluoride fiber that comprises the following components: 53mol. % of ZrF4, 20mol. % of BaF2, 4mol. % of LaF3, 4mol. % of AlF3 and 20mol. % of NaF. One end of the doubly coated ZBLAN fluoride fiber is connected with a high power fiber-doped pump laser, and a cavity resonator of Raman lasers is formed by a plurality of fiber Bragg grating pairs inscribed on two ends of the ZBLAN fiber. By using the stimulated Raman effect of ZBLAN fiber, the Stokes light in all phases generated by Raman frequency shift of pump light form resonance in the fiber Bragg grating pairs to finally realize output of mid-infrared laser. The invention has the advantages of simple and compact structure, high beam quality, high conversation rate, solves the problem that the traditional fiber laser is difficult to generate laser in mid-infrared section, and can be widely used in various fields such as military, medical treatment, environmental monitoring and the like.

A method and apparatus for measuring target gas concentrations in an atmosphere. The method and apparatus emit in the atmosphere a laser beam tuned to a molecular absorption line of a target gas, receive a reflected signal affected by gas absorption of the target gas in the atmosphere, divide and direct the received signal into a first optical path and a second optical path including in one of the paths a correlation gas cell filled with a predetermined concentration of the target gas, detect transmitted signals through the first optical path and the second optical path, and calculate a target gas concentration by comparing a first signal transmitted through the first optical path to a second signal transmitted through the second optical path. The apparatus includes a laser source tunable to a specific molecular absorption line of a target gas and configured to emit in the atmosphere a laser beam having a spectral bandwidth greater than a full width of the molecular absorption line of the target gas, a receiver configured to receive a reflected signal affected by gas absorption of the target gas in the atmosphere, and at least one detector configured to detect transmitted signals through the first optical path and the second optical path.

The invention discloses an intermediate / far infrared super-continuum spectrum fiber laser which relates to the field of laser photoelectrons. The intermediate / far infrared super-continuum spectrum fiber laser comprises a pulse fiber laser, a quartz photonic crystal fiber, a passive intermediate infrared chalcogenide glass fiber, a passive intermediate / far infrared chalcogenide glass fiber, a filter, an excitation source and a rare earth ion doped chalcogenide glass fiber, wherein a super-continuum spectrum laser is generated by the pulse laser emitted by the pulse fiber laser through the quartz photonic crystal fiber to excite the passive intermediate infrared chalcogenide glass fiber so as to generate an intermediate infrared super-continuum spectrum laser; the intermediate infrared super-continuum spectrum laser is filtered by the filter; the filtered intermediate infrared super-continuum spectrum laser is used as a seed resource laser and amplified through the rare earth ion doped chalcogenide glass fiber; and the amplified intermediate laser is used for exciting the passive intermediate / far infrared chalcogenide glass fiber so as to generate an intermediate / far infrared super-continuum spectrum laser with a wavelength of 5-14 micrometers. According to the intermediate / far infrared super-continuum spectrum fiber laser, the shortage of light sources of intermediate / far infrared lasers is solved and the output of the intermediate / far infrared super-continuum spectrum laser is realized.

The invention discloses a middle-infrared thulium-doped fiber laser amplifier which is composed of a seed light source, an optical isolator, a focusing lens, a pumping light source, a multi-path fiber coupler, double clad thulium-doped fiber, a collimating lens and a beam splitting plate. The position relationships of the components are as follows: the optical isolator, the focusing lens, the multi-path fiber coupler, the double clad thulium-doped fiber, the collimating lens and the beam splitting plate are sequentially arranged along the laser output direction of the seed light source, an input end of the seed optical fiber of the multi-path fiber coupler is positioned at the focus of the collimating lens, an output end of the seed optical fiber is welded with the double clad thulium-doped fiber, the other end of the double clad thulium-doped fiber is positioned at a front focus of the collimating lens, and the beam splitting plate and the output light beam of the collimating lens are arranged at an angle of 45 degrees. The laser amplifier has good heat dissipation characteristic, improves the pumping power and can obtain high-power mid-infrared laser output.