120 results about "Pulsed laser radiation" patented technology

A method for machining a transparent material by the non-linear absorption of pulsed laser radiation, in the region of a laser focus, includes the following steps: a laser wavelength of between 300 and 1000 μm is selected; and laser impulses having a temporally flat beam profile are applied. The method is characterized in that the irradiation intensity is selected from an interval pre-determined for the material to be machined, in which plasma is formed without plasma luminescence. An apparatus for laser treating a transparent material includes structure to set an irradiance and inspect the treatment as being within a defined interval.

A method of forming preform structures from fiber composite materials in an automated tape placement process, for subsequent resin infusion and heating. Pulsed laser radiation is directed into a nip region of a compaction roller during formation of a composite preform structure to selectively heat discrete areas on a resin veil of thermoplastic to an incoming fiber tape material and a surface of a substrate, to more precisely control tacking of the resin veil of thermoplastic to the fiber tape and the surface of a substrate in predetermined locations.

A method based on time-resolved, laser-induced fluorescence spectroscopy for the characterization and fingerprinting of petroleum oils and other complex mixtures. The method depends on exciting the wavelength-resolved fluorescence spectra of samples using ultraviolet pulsed laser radiation, measuring them at specific time gates within the temporal response of the excitation laser pulse, and comparing them in terms of their shapes alone without taking into account their relative intensities. The method provides fingerprints of crude oils without resorting to any kind of approximation, for distinguishing between closely similar crude oils of the same grade, and is useful in remote and non-remote setups, along with applications in fingerprinting blended and non-blended crude oils using different ultraviolet excitation wavelengths. Applications include estimating °API gravity of crude oils and monitoring degradation of mineral oils.

An apparatus for generating cut surfaces in the cornea of an eye in order to correct ametropia is provided, said apparatus comprising a laser unit, which can focus pulsed laser radiation into the cornea and move it therein in order to generate cut surfaces, and a control unit, which controls the laser unit for generating cut surfaces such that a predetermined lenticle to be removed is separated from the surrounding corneal material in the cornea by at least one cut surface, and that at least two mutually spaced apart cut surfaces are formed as opening cuts, each extending from the lenticle to the anterior corneal surface, the position and shape of the opening cuts being selected such that the opening cuts contribute to the correction of the ametropia of the eye or do not counteract the correction of the ametropia of the eye.

A method and delivery system are disclosed for creating an aqueous flow pathway in the trabecular meshwork, juxtacanalicular trabecular meshwork and Schlemm's canal of an eye for reducing elevated intraocular pressure. Pulsed laser radiation is delivered from the distal end of a fiber-optic probe sufficient to cause photoablation of selected portions of the trabecular meshwork, the juxtacanalicular trabecular meshwork and an inner wall of Schlemm's canal in the target site. The fiber-optic probe may be advanced so as to create an aperture in the inner wall of Schlemm's canal in which fluid from the anterior chamber of the eye flows. The method and delivery system may further be used on any tissue types in the body.

A method is disclosed for varying a pulse repetition rate of a passively q-switched laser while maintaining other characteristics of the laser radiation. The laser is optically pumped with a sequence of pump pulses which includes alterations between non-zero power levels and is characterized by two adjustable parameters. By simultaneously changing the adjustable parameters, the pulse repetition rate of the laser can be changed while maintaining the laser pulse energy, divergence of the pulsed laser radiation, and optical spectrum of the pulsed laser radiation at constant levels. In one embodiment, the sequence of pump pulses includes pump power offset which magnitude and/or duration is adjusted when the laser repetition rate is changed.

A method and apparatus delivers pulsed laser energy to a damage-sensitive surface. The pulse scanning method and apparatus allow for the deposition of a total dose of laser radiation that could not be attained by any conventional means without damaging the substrate being exposed. Using a solid-state diode pumped YAG laser and an enclosure with a gas ambient, laser pulses are scanned across a substrate according to one of several programmed approaches. Pulses are deposited that are non-adjacent in time, or non-adjacent in space, or both; conventional methods have the pulses adjacent in both time and space. Using the various approaches of the invention, the degree of spatial and temporal adjacency can be precisely controlled to permit significant laser radiation doses without causing any substrate damage. The present invention novel method and apparatus can be carried out by integrating a computer, laser and scan head with a small chamber into which gas can flow to permit a variety of surface reactions on damage-sensitive substrates that could otherwise not be conducted with conventional methods and systems.

A method of obtaining a series of images of a three-dimensional object by transmitting pulsed terahertz (THz) radiation through the entire object from a plurality of angles, optically detecting changes in the transmitted THz radiation using pulsed laser radiation, and constructing a plurality of imaged slices of the three-dimensional object using the detected changes in the transmitted THz radiation. The THz radiation is transmitted through the object as a scanning spot. The object is placed within the Rayleigh range of the focused THz beam and a focusing system is used to transfer the imaging plane from adjacent the object to a desired distance away from the object. A related system is also disclosed.

An apparatus for cutting brittle material comprises an aspheric focusing lens, an aperture, and a laser-source generating a beam of pulsed laser-radiation. The aspheric lens and the aperture form the beam of pulsed laser-radiation into an elongated focus having a uniform intensity distribution along the optical axis of the aspheric focusing lens. The elongated focus extends through the full thickness of a workpiece made of a brittle material. The workpiece is cut by tracing the optical axis along a cutting line. Each pulse or burst of pulsed laser-radiation creates an extended defect through the full thickness of the workpiece.

An apparatus for generating a correcting cut surface in the cornea of including a laser unit, which can focus and move pulsed laser radiation; a first contact element; and a control unit, controlling the laser unit which has a standard setting which, when a standard curvature is imposed upon corneal surface by the first contact element, would lead to a standard cut surface. The standard cut surface has a known curvature with respect to a reference surface. The curvature, with respect to the reference surface of the correcting cut surface to be generated deviates from the known curvature of the standard cut surface. The apparatus includes a second contact element adapted to generate the correcting cut surface, which cornea imposes an actual curvature deviating from the standard curvature, thus generating a cut surface using the standard setting results in the correcting cut surface to be generated.

The present disclosure is directed to systems and methods for protecting a semiconductor product or material from harmful effects of pulsed laser irradiation. In some embodiments, a thin sacrificial protective mask layer that expires after one laser processing operation is applied to the surface of the product or material to be laser-treated. The thin protective mask layer reflects, absorbs, or otherwise protects the underlying product or material from the energy of the laser.

The invention provides a device and a method for measuring the thermal distortion of a polarized beam splitter mirror. The device comprises a solid laser, a focusing lens, an energy optical fiber, an optical fiber shaping lens group, a beam splitter prism, a transmission plane mirror, a polarized beam splitter mirror, a zero-degree color filter, an attenuation light filter, a Fizeau interferometer and a computer, wherein the laser emitted from the solid laser is coupled to the energy optical fiber through the focusing lens, transmitted into a measuring room through the energy optical fiber, and is further radiated to the surface of the polarized beam splitter mirror in a theta angle through the optical fiber shaping lens group and the beam splitter prism; and the light emitted from the Fizeau interferometer is vertically radiated to the polarized beam splitter mirror through the light attenuation light filter and the zero-degree color filter. The device for measuring the thermal distortion of the polarized beam splitter mirror has the characteristics of simple structure, good stability and strong interference resistance, wavefront distortion of an optical film element under a laser radiation can be measured without contact, and moreover, the measurement can be carried out in continuous, single pulse or repeated pulse laser radiation.

A method for producing, trapping and manipulating a gas microbubble in liquid is disclosed. The method includes providing a pulsed laser source for generating a pulsed laser radiation and focusing optics; and focusing a pulsed laser radiation to a focal zone within the liquid, with energy exceeding the threshold of optical breakdown in the liquid at the focal zone. It is also suggested to use focusing optics to focus the laser beam to a focal point at a depth close to the compensation depth of the focusing optics for spherical aberration.

The invention discloses an in-vivo laser damage automatic and quick detection device for an optical element. The in-vivo laser damage automatic and quick detection device comprises the optical element to be detected arranged on a mobile platform, a pulse laser radiation system consisting of an Nd:YAG laser device and a first focusing lens which are sequentially arranged, an HeNe laser lighting system consisting of a first HeNe continuous laser device, a second focusing lens, a second HeNe laser device and a third focusing lens, and a damage detection system consisting of an aperture diaphragm, a scattered light collection lens group, a visual field diaphragm and a photoelectric detector which are coaxial sequentially, wherein the output end of the photoelectric detector is connected with the input end of a computer; and the output end of the computer is connected with the control ends of the Nd:YAG laser device and the mobile platform through a data output card. The in-vivo laser damage automatic and quick detection device is suitable for automatic and quick detection and judgment for in-vivo damages of optical elements of various types.

This patent describes an optical element, which converts incident linearly or circularly polarized visible light into radially or azimuthally polarized light beam. The polarization converter is a single optical element, produced by direct laser writing technique in an optically transparent substrate. Direct laser writing based on ultra-short pulsed laser radiation forms form birefringence self-assembled nanogratings in optically transparent material, such as fused silica. The period of gratings is smaller than wavelengths of a visible light.

The invention provides an ultrasonic, photoacoustic and fluorescent three-mode imaging system. The ultrasonic, photoacoustic and fluorescent three-mode imaging system comprises a laser light source module, a motion scanning module, a data acquisition module and a control processing module; the laser light source module is used for providing pulsed laser radiation to an imaging sample and enablingthe imaging sample to generate photoacoustic and fluorescent signals and sending synchronous trigger signals to the data acquisition module and the control processing module; the motion scanning module is used for performing three-dimensional scanning on the sample according to preset motion parameters; the data acquisition module is used for acquiring the photoacoustic/ultrasonic/fluorescent signals generated from the sample; the control processing module is used for receiving trigger pulse signals of a pulsed laser light source, enabling a motion scanning device to scan a target sample according to control instruments, processing received data of the target sample and fusing photoacoustic/ultrasonic/fluorescent images to acquire multimodal reconstructed images. By the arrangement, scanning time in imaging is reduced, and imaging resolution and imaging speed of the imaging system are increased.