Abstract: A nonvolatile semiconductor memory device comprises: a memory cell region having a memory cell disposed therein; a peripheral region including a first stepped structure in which an end of a lower first layer is further from the memory cell region than is an end of an upper first layer; and a second stepped structure disposed on the first stepped structure, in which an end of a lower third layer is disposed further from the memory cell region than is an end of an upper third layer, a length in a second direction being shorter than a length in the second direction of the first layer or the second layer contacted by the second stepped structure, and a length in a third direction of the second stepped structure being shorter than a length in the third direction of the first layer or the second layer contacted by the second stepped structure.

Abstract: An optical pulse train generator 10 includes beat light generation means 11 for generating a beat light 21 having a predetermined repeated frequency, a highly nonlinear fiber 12 for generating a pulse train 22 formed by adding a side mode to the beat light 21 by a four-wave mixing (FWM), and a band pass filter (BPF) 13 for adjusting a power balance of the side mode of the pulse train 22 so as to shape the frequency spectrum.

Abstract: An electromagnetic pumped alkali metal vapor cell system is provided. The system comprises a vapor cell and windings. The vapor cell contains alkali metal and a buffer. The windings are positioned around the vapor cell and are configured to create an electromagnet field in the vapor cell when an AC signal is applied to the windings. The electromagnetic field pumps unexcited alkali vapor into unionized D1 and D2 states.

Abstract: A laser device which can be used as a light source for an exposure device, can be downsized, and is easy to maintain. A laser beam (LB6) emitted from a DFB (Distributed feedback) semiconductor laser, for example, and amplified by an optical fiber amplifier is passed through non-linear optical crystals (502, 503, 504) to be sequentially doubled in frequency to thereby generate an ultraviolet-region laser beam (LB5) consisting of an octuple wave. A GdYCOB, that is, GdxY1?xCa4O(BO3)3 crystal (0?×?1) is used for the non-linear optical crystal (503) for a double wave-to-quadruple wave conversion, and a KAB, that is, K2Al2B4O7 crystal for the non-linear optical crystal (504) for a quadruple wave-to-octuple wave conversion. The non-linear optical crystals (502-504) are all fine-tuned in phase match angle by temperature controllers (521-523) respectively.

Abstract: Methods and systems for laser-based processing of materials are disclosed wherein a scalable laser architecture, based on planar waveguide technology, provides for pulsed laser micromachining applications while supporting higher average power applications like laser welding and cutting. Various embodiments relate to improvements in planar waveguide technology which provide for stable operation at high powers with a reduction in spurious outputs and thermal effects. At least one embodiment provides for micromachining with pulsewidths in the range of femtoseconds to nanoseconds. In another embodiment, 100 W or greater average output power operation is provided for with a diode-pumped, planar waveguide architecture.

Abstract: A semiconductor laser module has a Fabry-Perot type semiconductor laser device, an optical fiber, and first and second lenses. The tip of the optical fiber, on which the laser beam falls, is askew polished. The optical fiber is fixed in such a manner that the axis of the optical fiber makes an angle with respect to an optical axis of the laser beam. Coatings that avoid reflection are formed on the tip of the optical fiber, and on the first and second lenses.

Abstract: The present invention provides a laser machining apparatus in a simple structure which can properly carry out laser machining by irradiating a laser beam easily at a predetermined energy density to a machining-target site in a predetermined range, and in addition, which can be downsized and can be kept with easy maintenance and has enhanced durability. The apparatus includes: a semiconductor stack 1 comprising a plurality of semiconductor laser elements; and a controller for controlling emission of the laser beam emitted from each of the semiconductor laser elements. The semiconductor stack 1 is divided into a plurality of blocks B11, B12, B13, B14 in correspondence with the machining-target site of a work piece. The controller controls the irradiation of the laser beam from each of the blocks B11, B12, B13, B14 to be changeable in terms of time.

Abstract: Provided is a small-sized laser light generating apparatus capable of oscillating continuous light with a range of wavelengths of about 200 nm or less with stability at high conversion efficiency. Light with wavelength &lgr;1 and light with wavelength &lgr;2 outputted from a first laser light generator and a second laser light generator are introduced into a first resonator and a second resonator, respectively, and then a nonlinear optical device included in both the first and second resonators generates light with wavelength &lgr;3 through sum-frequency mixing of these two incoming light beams. The light with the wavelength &lgr;1, the light with the wavelength &lgr;2 and the light with the wavelength &lgr;3, which are spatially separated from one another, enter into and exit from the nonlinear optical device and have different optical paths.

Abstract: In an excimer laser oscillation apparatus including a laser chamber (20) constituted by a laser tube (2) for storing a laser gas containing a gas mixture of at least one inert gas selected from the group consisting of Kr, Ar, and Ne, He and F2 gas, and an optical resonator consisting of a pair of reflection mirrors (5, 6) arranged to sandwich the laser chamber (20) therebetween, the inner surface of the laser chamber (20) for storing the laser gas has a reflection-free surface with respect to light of a desired wavelength of 248 nm, 193 nm, or 157 nm, and the uppermost surface of the inner surface consists of a fluoride, and a means (waveguide 1) for introducing a microwave for exciting the laser gas in the laser chamber (20) is prepared.

Abstract: An electron beam pumped semiconductor laser screen and an associated fabrication method are described which provide a display screen that has a relatively long operating lifetime, is less expensive to produce, and operates at lower electron voltages and near room temperature conditions. The laser screen includes a multi quantum well active gain region having quantum wells of GaInP and barrier layers of (AlxGa1-x)InP, thereby permitting operation in the visible, red spectrum. Moreover, the first layer epitaxially grown on the sacrificial substrate is an etch stop layer of (GaxAl1-x)yIn1-yP that acts as an etch stop during the subsequent etching of the sacrificial substrate and may also be used to adjust the cavity length to the correct resonance condition. The laser screen also includes an output mirror having alternating layers of two different compositions of GaxAl1-xAs that are epitaxially grown on the multi quantum well active gain region.

Abstract: An adjustable mounting unit for an optical element of a gas laser is provided. The typical gas laser for which the mounting unit will be used comprises a tube having a first end wall at one end and a second end wall at the other end, an optical axis extending longitudinally through the tube, and a port in the first end wall through which the optical axis passes. The mounting unit includes a rigid support structure having an aperture therein and an optical element mounted within the aperture. In addition, at least three adjustable mounting devices are used to attach the support structure to the laser tube. The mounting points are preferably selected so that they are displaced in an axial direction by substantially the same amount due to dimensional changes in the laser occurring during operation of the laser. When attached to the laser, the rigid support is spaced apart from the laser tube to allow for the adjustment of the angular positioning of the optical element.

Abstract: The beam path [80] of a laser source [10] is first pre-aligned to a predetermined reference, and then the optical axis [90] of the beam delivery system [40, 50] of a laser material processing platform [20] is pre-aligned to the pre-aligned beam path of the laser source such that the two coincide. If the laser beam [80] is invisible, a laser simulator [72] having a visible pre-aligned beam may be used instead.

Abstract: A mode locked semiconductor laser that can generate relatively high-power output pulses. The semiconductor mode locked laser is formed from an array of optical amplifiers that are coupled to a common resonant cavity by way of an optical channelizer or wavelength division multiplexer (WDM). By utilizing an array of optical amplifiers, the output pulses will have a relatively higher power than known mode locked lasers. As such, the mode locked semiconductor laser in accordance with the present invention does not depend on the power handling capability of the individual optical amplifiers and allows the average output power to be scaled, for example, up to the kilowatt range using semiconductor optical amplifiers. A mode locked laser in accordance with the present invention can be implemented with active mode locking, passive mode locking or a hybrid of the two. In embodiments utilizing active mode locking, the output pulse shape can be tailored by the amplifier drive current distribution.

Abstract: An object is to obtain an even energy distribution of a laser beam in one direction, thereby conducting a uniform laser annealing on a film. A laser irradiation apparatus comprising: a lens for dividing a laser beam in one direction; and an optical system for overlapping the divided laser beam, characterized in that the shape of the laser beam entering into the lens has edges vertical to the above-mentioned direction.

Abstract: In a semiconductor laser device, a first section including a single-mode waveguide and a second section including N (N=2, 3 . . . ) single-mode waveguides are provided. A third section including a 1×N multi-mode interference type waveguide is provided and has an end connected to the first section and has another end connected to the second section.

Abstract: A semiconductor light emitting device has a stacked structure including an n-type clad layer, an active layer, and a p-type clad layer on an InP substrate. The p-type clad layer is made from an MgZnSeTe-based compound semiconductor lattice-matched with InP. The n-type clad layer is made from a compound semiconductor lattice-matched with InP and selected from an MgZnSeTe-based compound semiconductor, an MgZnCdSe-based compound semiconductor, and an MgCdSSe-based compound semiconductor.

Abstract: A laser includes a lasing medium having a slab geometry, a waveguide arrangement either side of the slab, mirrors forming an unstable sub-resonator acting in a plane perpendicular to the waveguide, and a concave mirror arrangement acting on light incident on it launched from the waveguide, and thereby transformed from waveguide light to free space light, to redirect and retransform a portion of said light to be re-entrant waveguide light constituting the unstable sub-resonator round-trip self-replicating light. The unstable sub-resonator preferably includes a folding mirror to direct light towards the concave mirror, and the concave mirror is preferably partially transmissive.