Abstract: A surface-emitting distributed feedback (SEDFB) laser is provided with a “fan-shaped” grating comprising a group of generally straight lines radiating from a central point that is away from the center of the gain. Such a grating provides better stability against self-induced filamentation and dynamic instabilities that limit achievable beam quality, especially in lasers having a stripe length greater than 1 mm.

Abstract: A prismatic device for reforming the cross section of the beam emitted along a semiconductor laser bar stripe by deflecting successive segments of the emitted beam in directions making acute angles with the longitudinal axis of the emitted beam and redirecting the deflected beam segments through layers of glass into an array of parallel beam segments.

Abstract: A laser system is provided comprising of a laser source including a laser stabilizing control loop and a laser housing, the laser source producing an output beam. The laser system includes a wavelength selective optical member positioned in the laser housing, the wavelength selective optical member adjusting wavelength and output power of the output beam in response to wavelength or power fluctuations of the laser source due to intrinsic aging of the laser source or due to extrinsic local environmental changes. In some embodiments, the laser system is miniaturized and the wavelength selective optical members supports a zero beam path offset configuration.

Abstract: A high power, diode pumped laser has a Nd:YVO4 gain media. Scaling to higher powers is achieved with the use of a low doped gain media, increasing the length of the gain media as well as increasing the pump volume. Passive cooling is extended to output powers of 10 W or greater.

Abstract: A solid state laser in which a slab of lasing material is held within an optical resonator is disclosed. The length of the slab in parallel to the optical axis of the resonator is between 5 and 1,000 mm, the width and thickness of the slab are 1-50 mm and 0.01-2 mm, respectively. The slab is designed in a way that causes the pump light to be confined when side- or end pumped by diode lasers. This is accomplished by either polishing the two largest area faces (referred to as upper and lower sides) of the slab and coating them with a material (dielectric or metallic) that is highly reflective at the emission wavelength, or by sandwiching the slab between dielectric materials that comprise a lower refractive index compared to the index of the slab. In alternative embodiments, the thin dimension of the slab may be selected so as to either guide the signal light or to allow free space propagation.

Abstract: The invention is a double chirped mirror and a method of constructing a double chirped mirror for a frequency range of electromagnetic radiation, comprising specifying a design including a plurality of layers, the plurality of layers being transparent to the electromagnetic radiation and having refractive indices which vary between layers in the plurality of layers, and wherein for a first set of layers the optical thickness of alternate layers in the set of layers varies monotonically and the total optical thickness of a layer and the two adjacent half layers in the set of layers varies monotonically. The design is optimized by adjusting the optical thickness of layers in the plurality of layers.

Abstract: A lithography system for providing interconnections of integrated circuits on a substrate includes a laser system with a high reflector and an output coupler that define an oscillator cavity. A gain medium and a mode locking device are positioned in the oscillator cavity. A diode pump source produces a pump beam that is incident on the gain medium. A processor is coupled to the laser system and stores a representation of interconnections for the integrated circuit. An output beam directing apparatus is coupled to the processor and directs the output beam to the substrate and form the interconnections.

Abstract: An amplifier uses a two-dimensional array of cw diodes to produce a pump beam. A coupler is positioned to receive the pump beam. The coupler reduces a cross-sectional dimension of the pump beam and creates a modified pump beam. A vanadate gain medium is positioned adjacent to the coupler. The vanadate gain medium absorbs at least a portion of the modified pump beam and is positioned to receive an input beam from an input beam source and produce an amplified output beam.

Abstract: Fiber delivery systems are desirable to provide convenient delivery of an output beam from a laser system to a target distanced from the source. For ultra-short pulse lasers, a limiting factor in fiber delivery is the dispersion of the optical fiber. A fiber delivery system for ultra-short pulses that uses a photonic crystal fiber to Fprovide the appropriate dispersion is described.

Abstract: An inspection apparatus includes a laser system. The laser system has a high reflector and an output coupler that define an oscillator cavity which produces an output beam. A gain medium and a mode locking device are positioned in the oscillator cavity. A diode pump source produces a pump beam that is incident on the gain medium. An output beam directing apparatus directs the output beam to the surface of the article. A surface flaw at the surface of the article produces scattered light from at least a portion of the output beam incident on the surface flaw. A detector is positioned to detect the scattered light.

Abstract: Disclosed is a laser system including a high reflector and an output coupler defining a resonator; a gain medium positioned in the resonator that produces optical gain at more than two desired wavelengths; a coarse selection system, positioned in the resonator and coupled to the gain medium, that produces single transverse modes at the desired wavelengths, with transmission values at the desired wavelengths selected such that power output at the desired wavelengths is maximized, and with transmission values at undesired wavelengths selected to retard lasing at the undesired wavelengths; and a fine selector positioned in the resonator and coupled to the gain medium, having a optical length such that all of the desired wavelengths are substantially simultaneously resonant within the optical length; whereby an output beam is generated. Also disclosed are full-color holography systems and three-dimension laser Doppler velocimetry systems incorporating the inventive laser system.

Abstract: The invention is a double chirped mirror and a method of constructing a double chirped mirror for a frequency range of electromagnetic radiation, comprising specifying a design including a plurality of layers, the plurality of layers being transparent to the electromagnetic radiation and having refractive indices which vary between layers in the plurality of layers, and wherein for a first set of layers the optical thickness of alternate layers in the set of layers varies monotonically and the total optical thickness of a layer and the two adjacent half layers in the set of layers varies monotonically. The design is optimized by adjusting the optical thickness of layers in the plurality of layers.

Abstract: A diode pumped, multi axial mode, intracavity doubled laser has at least two resonator mirrors that define a resonator cavity. A Nd:YVO4 laser crystal and a LBO doubling crystal are positioned in the resonator cavity. A diode pump source supplies a pump beam to the laser crystal and produces a laser crystal beam with at least three axial modes that are incident on the doubling crystal. A frequency doubled output beam is generated with an output power of at least 1 watt.

Abstract: A laser writing system includes a high reflector and an output coupler that define an oscillator cavity. A gain medium and a mode locking device are positioned in the oscillator cavity. A diode pump source produces a pump beam that is incident on the gain medium and an output beam is produced. A support holds a workpiece. Means are provided for directing the output beam across the workpiece.

Abstract: A diode pumped, multi axial mode, intracavity doubled, intracavity tripled laser, includes at least two resonator mirrors defining a resonator cavity. A laser crystal and a doubling crystal are positioned in the resonator cavity. A tripling crystal is also positioned in the resonator cavity. A diode pump source supplies a pump beam to the laser crystal and produces a laser crystal beam with a plurality of axial modes that are incident on the doubling crystal. This produces a frequency doubled output beam. Further, a diode pumped, multi axial mode, intracavity nonlinearly-converted laser is provided and includes at least two resonator mirrors defining a resonator cavity, a laser crystal and a nonlinear conversion apparatus positioned in the resonator cavity. A nonlinear conversion apparatus is also positioned in the resonator cavity.

Abstract: A system is provided that delivers sub-picosecond pulses. The system includes a source that produces an output beam of sub-picosecond pulses at a wavelength no greater than 1.27 microns. A photonic crystal fiber is coupled to the source to receive the output beam. The photonic crystal fiber delivering pulses at the target with a pulsewidth less than 2 times a pulsewidth of the source. A first optical device is positioned between the source and the fiber. The first optical element couples the output beam into an input end of the fiber. A second optical device is positioned at an output end of the fiber that delivers the output beam to a selected target.

Abstract: A high power, diode pumped laser has a Nd:YVO4 gain media. Scaling to higher powers is achieved with the use of a low doped gain media, increasing the length of the gain media as well as increasing the pump volume. Passive cooling is extended to output powers of 10 W or greater .

Abstract: In a method an an apparatus for automatic inspection of moving surfaces using at least three different illumination/observation channels, the surface to be inspected under a bright field condition is illuminated by a first beam of light from a first light source. The light of the first beam of light reemitted from the surface is received by a light sensitive sensor device to obtain a first signal. Then, the surface is illuminated under a dark field condition by a second beam of light and by a third beam of light from a second and a third light source, respectively, the first, second and third beams of light having different characteristics. The light of the second beam of light and the light of the third beam of light, respectively, reemitted from the surface are received by the light sensitive sensor device to obtain a second signal and a third signal. Finally, a physical property of the surface is derived from the first, second and third signals.

Abstract: A point of sale (POS) bar code scanner such as in common use in retail stores includes provision for reading bar coded redemption coupons (or other bar coded documents redeemable for value) in a manner secure from a human operator. Integration of functions between the POS scanner and the coupon reader varies with different embodiments described. Through software associated with bar code decoding logic, a comparison is made between information on a validation coupon and information on items presented for purchase, and a decision is made as to whether the redemption coupon is valid and redeemable in this transaction. In one embodiment, the bar code scanner simply receives the redemption coupon face down on the product scanner window, and integrated decode logic of the scanner identifies the bar code as belonging to a redemption coupon, then makes the comparison and validation of the coupon for the particular transaction.