1208 results about "Laser oscillator" patented technology

The present invention relates to the apparatus, system and method for dicing of semiconductor wafers using an ultrafast laser pulse of femtosecond and picosecond pulse widths directly from the ultrafast laser oscillator without an amplifier. Thin and ultrathin simiconductor wafers below 250 micrometer thickness, are diced using diode pumped, solid state mode locked ultrafast laser pulses from oscillator without amplification. The invention disclosed has means to avoid/reduce the cumulative heating effect and to avoid machine quality degrading in multi shot ablation. Also the disclosed invention provides means to change the polarization state of the laser beam to reduce the focused spot size, and improve the machining efficiency and quality. The disclosed invention provides a cost effective and stable system for high volume manufacturing applications. An ultrafast laser oscillator can be a called as femtosecond laser oscillator or a picosecond laser oscillator depending on the pulse width of the laser beam generated.

An exposure apparatus has a laser device that is small, easy to maintain, and capable of producing an output that is unlikely to be affected by optical surges occurring in the beginning of operation. A single-wavelength laser oscillator (11) supplies a laser beam (LB1) to a fiber optic amplifier (13) through an optical modulator (12). The amplified laser beam is split by splitters (14, 16-1 to 16-m), amplified by optical amplifier units (18-1 to 18-n) and supplied through a fiber bundle (19) to a wavelength converter (20), which in turn converts the split beams into ultraviolet laser radiation (LB5) for use as exposure light. The optical modulator (12) outputs light pulses during the generation of ultraviolet light. The optical modulator (12) also produces laser radiation during the absence of ultraviolet light, but the laser radiation has substantially the same average output and a considerably low peak compared with that during the generation of ultraviolet light.

A control system and apparatus for use with an ultra-fast laser is provided. In another aspect of the present invention, the apparatus includes a laser, pulse shaper, detection device and control system. A multiphoton intrapulse interference method is used to characterize the spectral phase of laser pulses and to compensate for any distortions in an additional aspect of the present invention. In another aspect of the present invention, a system employs multiphoton intrapulse interference phase scan. Furthermore, another aspect of the present invention locates a pulse shaper and/or MIIPS unit between a spectral dispersion point in a laser oscillator and an output of a laser amplifier.

A control system and apparatus for use with an ultra-fast laser is provided. In another aspect of the present invention, the apparatus includes a laser, pulse shaper, detection device and control system. A multiphoton intrapulse interference method is used to characterize the spectral phase of laser pulses and to compensate any distortions in an additional aspect of the present invention. In another aspect of the present invention, a system employs multiphoton intrapulse interference phase scan. Furthermore, another aspect of the present invention locates a pulse shaper and/or MIIPS unit between a laser oscillator and an output of a laser amplifier.

A laser producing high energy ultrashort laser pulses comprises a normal dispersion segment, a gain segment, an anomalous dispersion segment with negligible nonlinearity and an effective saturable absorber arranged to form a laser cavity. Each segment is optically interconnected so that a laser pulse will propagate self-similarly therein. (A pulse that propagates in a self-similar manner is sometimes referred to as a “similariton.”) With this laser the limitations of prior art laser oscillators are avoided. Also provided are means for pumping the gain medium in the laser cavity, and means for extracting laser pulses from the laser cavity. The laser cavity is preferably a ring cavity. Preferably the laser is configured to achieve unidirectional circulation of laser pulses therein. This configuration is scalable to much higher pulse energy than lasers based on soliton-like pulse shaping.

A novel method for high power optical amplification of ultrashort pulses in IR wavelength range (0.7-20 Ãm) is disclosed. The method is based on the optical parametric chirp pulse amplification (OPCPA) technique where a picosecond or nanosecond mode locked laser system synchronized to a signal laser oscillator is used as a pump source or alternatively the pump pulse is created from the signal pulse by using certain types of optical nonlinear processes described later in the document. This significantly increases stability, extraction efficiency and bandwidth of the amplified signal pulse. Further, we disclose five new practical methods of shaping the temporal and spatial profiles of the signal and pump pulses in the OPCPA interaction which significantly increases its efficiency. In the first, passive preshaping of the pump pulses has been made by a three wave mixing process separate from the one occurring in the OPCPA. In the second, passive pre-shaping of the pump pulses has been made by spectral filtering in the pump mode-locked laser or in its amplifier. In the third, the temporal shape of the signal pulse optimized for OPCPA interaction has been actively processed by using an acousto-optic programmable dispersive filter (Dazzler) or liquid crystal light modulators. In the fourth alternative method, the signal pulse intensity envelope is optimized by using passive spectral filtering. Finally, we disclose a method of using pump pulses which interact with the seed pulses with different time delays and different angular orientations allowing the amplification bandwidth to be increased. In addition we describe a new technique for high power IR optical beam delivery systems based on the microstructure fibres made of silica, fluoride or chalcogenide glasses as well as ceramics. Also we disclose a new optical system for achieving phase matching geometries in the optical parametric interactions based on diffractive optics. All novel methods of the ultrashort optical pulse amplification described in this disclosure can be easily generalized to other wavelength ranges.

In conducting laser annealing using a CW laser or a quasi-CW laser, productivity is not high as compared with an excimer laser and thus, it is necessary to further enhance productivity. According to the present invention, a fundamental wave is used without putting laser light into a non linear optical element, and laser annealing is conducted by irradiating a semiconductor thin film with pulsed laser light having a high repetition rate. A laser oscillator having a high output power can be used for laser annealing, since a non linear optical element is not used and thus light is not converted to a harmonic. Therefore, the width of a region having large grain crystals that is formed by scanning once can be increased, and thus the productivity can be enhanced dramatically.

A laser beam having homogeneous intensity distribution is delivered without causing interference stripes of a laser to appear on an irradiation surface. A laser beam emitted from a laser oscillator passes through a diffractive optical element so that the intensity distribution thereof is homogenized. The beam emitted from the diffractive optical element then passes through a slit so that low-intensity end portions in a major-axis direction of the beam are blocked. Subsequently, the beam passes through a projecting lens and a condensing lens, so that an image of the slit is projected onto the irradiation surface. The projecting lens is provided so that the slit and the irradiation surface are conjugated. Thus, the irradiation surface can be irradiated with the laser having homogeneous intensity while preventing the diffraction by the slit.

A light source emits a laser beam to the object through an output end. An optical system is placed between the output end and the object. The optical system adjusts the energy of the laser beam emitted, through the output end, onto a unit area for a unit time. The energy of the beam spot on the object enables cutting or bending of the object. The optical system serves to adjust the energy of the laser beam irradiated to the object. The energy of the laser beam instantly changes as compared with the case where the energy of the laser beam is adjusted based on a driving voltage applied to a laser oscillator. The object is thus processed by using the laser beam with high accuracy.

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.

It is an object of the present invention to provide a laser irradiation apparatus being able to irradiate the irradiation object with the laser beam having homogeneous energy density without complicating the optical system. The laser irradiation apparatus of the present invention comprises a laser oscillator, an optical system for scanning repeatedly a beam spot of the laser beam emitted from the laser oscillator in a uniaxial direction over the surface of the irradiation object, and a position controlling means for moving the position of the irradiation object relative to the laser beam in a direction perpendicular to the uniaxial direction.

An extreme ultra violet light source apparatus in which both a mechanism of supplying a droplet target to a laser application position at a high speed and a mechanism of trapping charged particles generated from plasma are managed without disturbing a track of the target. The apparatus includes: a target nozzle that injects a target material toward a plasma generation point; an electric charge supply unit that charges the injected target material; an acceleration unit that accelerates the charged target material; a laser oscillator that applies a laser beam to the target material at the plasma generation point to generate plasma; and electromagnets that form a magnetic field at the plasma generation point such that the magnetic field has substantially straight lines of magnetic flux in substantially parallel with a traveling direction of the target material in the track of the target material.

A miter saw having first and second laser oscillators. A base is provided for mounting a worpiece. A fence extends in a lateral direction and is fixed to the base and has a front surface to which the workpiece is to be abutted. A cutting unit rotatably supports a circular saw blade. A support section is supported on the base and is pivotably supports the cutting unit movable toward and away from the base. The first laser oscillator is provided at the base for irradiating a first laser beam to the front side of the workpiece. The second laser oscillator is provided at the support section for irradiating a second laser beam to a rear side of the workpiece.

The application provides a low noise fiber laser frequency combs device with controllable carrier envelope phase shift frequency. The low noise fiber laser frequency combs device with controllable carrier envelope phase shift frequency comprises an optical path structure and a circuit structure, wherein the optical path structure comprises an oscillator, an acousto-optic frequency shifter, an optical fiber amplifier, a pulse compressor, an optical fiber spread spectrum device and a coherent heterodyne beat device; and the circuit structure comprises a feed-forward circuit control phase device and a phase-locked loop circuit control repetition frequency device. The fiber laser oscillator can ensure long-time operation of a system, so that the stability of the system is superior to that of a system adopting a solid laser oscillator; through the technologies of optimizing intracavity net dispersion of the fiber oscillator, introducing an inner cavity modulator in the oscillator, adopting the feed-forward acousto-optic frequency shifter, and the like, the low noise fiber laser frequency combs device can be realized; and meanwhile, due to the application of the acousto-optic frequency shifter, the carrier envelope phase shift frequency of the optical frequency combs can be accurately regulated, so that the optical frequency combs device with precise phase position regulation and secular stability is provided for realizing applications such as optical frequency standard, attosecond science and non-linear optics.

A first laser beam is emitted from a first laser oscillator in a pulsed manner at a high repetition frequency, and converged onto a substrate by a first intermediate optical system 2 so as to form a slit-like first beam spot. A second laser beam is emitted from a second laser beam oscillator in a pulsed manner to rise precedent to and fall subsequent to the first laser beam, and converged onto the substrate by a second intermediate optical system so as to form a second beam spot similar in configuration to the first beam spot and to contain the first beam spot. Crystallization of a semiconductor thin film on the substrate is carried out while the substrate or the first, second beam spots are moved. Thereby, the whole semiconductor thin film is formed into a crystal surface that has grown in one direction and free from ridges. Thus, the semiconductor thin film has an extremely flat surface, extremely few defects, large crystal grains and high throughput.

The invention provides a laser processor and a laser processing method, and uniform laser processing can be done whatever the laser irradiated surface state of a processed object is. The laser processor that applies laser processing to the processed object is characterized in comprising a chunk table that holds the processed object; a laser beam irradiation member that includes a laser oscillator and a processing head, wherein the processing head a condenser lens that condenses laser beam oscillated by the laser oscillator; a reflected light amount detection member that detects reflected light amount of the laser beam that is irradiated from the laser beam irradiation member to the processed object held on the chunk table; and an output adjusting member that adjusts output of the laser beam oscillated by the laser oscillator based on the reflected light amount detected by the reflected light amount detection member.

Laser beam L oscillated by a laser oscillator 4 is guided by an optical fiber 12 constituting laser-guiding means 7 to a processing head 6, a liquid passageway 25 to which a high-pressure liquid is supplied by a high-pressure pump 5 is formed in the processing head, and this high-pressure liquid is jetted in the form of a liquid column W from a jet hole 24 of a jet nozzle 23 provided at a lower end of the processing head 6.

The optical fiber is exposed inside of the liquid passageway, and a tip of a fiber core 12a of the optical fiber projects beyond a fiber clad 12b, and is close to the vicinity of the jet hole.

The laser beam irradiated from the fiber core is guided to the liquid column after it is reflected on a first inclined surface 24a formed on the jet hole, and processing on the workpiece 2 is performed.

The laser beam can easily be guided to the liquid column.