Abstract: The meters of coiled silica fiber in conventional R-EDFAs is replaced with an ultra-short high-gain waveguides formed of co-doped erbium-ytterbium multi-component glass a few centimeters in length. The compact R-EDA is pumped using non-conventional multi-mode pumps that couple to the waveguide cladding. The multi-component glasses support doping concentrations of the rare-earth ions erbium and ytterbium far in excess of levels believed possible with conventional glasses. These dopant levels in combination with the reflective scheme make a compact R-EDA with sufficient amplification possible.

Abstract: A multimode diode package and pump-coupler package are provided with a beam rotator that facilitates efficient packaging of a multimode diode laser with a side-coupled optical fiber. The beam rotator comprises a pair of reflective surfaces that perform/a pair of “off-plane bounces” to rotate the beam's fast axis. In an XYZ coordinate system, if the diode lies in the XZ-plane and emits the beam along the Z-axis with its fast-axis along the Y-axis, the first reflective surface folds the beam along the Y-axis and its fast-axis along the Z-axis. The second reflective surface folds the beam along the X-axis and leaves the fast-axis along the Z-axis. The fiber is mounted in the XZ-plane along the Z-axis parallel to the fast-axis.

Abstract: A deep-ultraviolet violet laser beam which is a harmonic and is generated inside a nonlinear optical element (101) is emitted outside the nonlinear optical element (101), being spaced from a green laser beam, which is a fundamental wave. The green laser beam emitted outside the nonlinear optical element (101) is reflected by an input-coupling mirror (102) and applied again into the nonlinear optical element (101) in order to form a closed optical path for the fundamental wave. Also, the deep-ultraviolet laser beam emitted outside the nonlinear optical element (101) is reflected by a reflecting mirror (28) other than the input-coupling mirror (102) in order to emit the deep-ultraviolet laser beam from a deep-ultraviolet laser beam-generating section (20).

Abstract: A laser beam generation apparatus includes a solid state laser medium having first and second optically polished planes provided opposed with each other to allow a laser beam to be pumped to pass out of one of the first and second optically polished planes. At least one third optical polished plane which is different from the first and second optically polished planes is also provided. A pumping beam source emits a pumping light beam to pump the laser medium and impinges the pumping light source to be incident on the at least one third optically polished plane. Further, the pumping laser beam is provided at an incident angle substantially equal to the Brewster angle.

Abstract: A compact, low-cost mid-gain Erbium Micro-Fiber Amplifier (EMFA) is provided by multi-mode pumping a micro fiber formed from a specialty multi-component glass and highly co-doped with Er:Yb. The specialty glass exhibits a much higher core absorption coefficient than standard glasses. As a result, the lower order modes are rapidly absorbed in the fiber core. The abrupt change in the mode profile perturbs the higher order modes and mode couples them into the lower order modes within a very short length of fiber, less than 20 cm. This “absorptive mode coupling” effect can double the absorption efficiency of a circular symmetric micro fiber and extend the length over which such a highly doped fiber can be efficiently inverted. The combination of multi-mode pumping with short fiber lengths reduces the form factor and cost of EMFAs.

Abstract: The meters of coiled silica fiber in conventional R-EDFAs is replaced with an ultra-short high-gain waveguides formed of co-doped erbium-ytterbium multi-component glass a few centimeters in length. The compact R-EDA is pumped using non-conventional multi-mode pumps that couple to the waveguide cladding. The multi-component glasses support doping concentrations of the rare-earth ions erbium and ytterbium far in excess of levels believed possible with conventional glasses. These dopant levels in combination with the reflective scheme make a compact R-EDA with sufficient amplification possible.

Abstract: A multi-port optical amplifier chip has an inner cladding layer sandwiched between a pair of outer cladding layers, a plurality of active core elements disposed substantially within the inner cladding layer to receive optical signals at respective input ports and transmit amplified optical signals at respective output ports, a pair of reflecting surfaces on opposing sides of the inner cladding and at least one pump source. The pump source directs pump light into the inner cladding layer where it is confined to bounce back-and-forth across the active core elements thereby enhancing the absorption of pump light into the core elements, hence increasing gain. Greater than 5 dB over the C-band (1930 nm-1965 nm) in less than 10 cm is expected with a phosphate glass material co-doped with greater than 2 weight percent Erbium and 10 weight percent Ytterbium. A number of fiber drawing based approaches are contemplated for manufacturing the amplifiers to achieve this performance and reduce cost.

Abstract: A total internal reflection (TIR) coupler for side coupling pump light into a fiber for use in an amplifier or laser is mounted on a flat surface of the fiber's inner cladding. The TIR coupler has a reflecting surface that forms an angle of taper a with the inner cladding, which is effective to reflect pump light at a preselected angle of incidence &thgr;inc and satisfy a TIR condition at its reflecting surface for folding pump light into the fiber. The pump light is launched into the fiber at an angle that also satisfies a TIR condition for guiding pump light inside the inner cladding.

Abstract: A deep-ultraviolet violet laser beam which is a harmonic and is generated inside a nonlinear optical element (101) is emitted outside the nonlinear optical element (101), being spaced from a green laser beam, which is a fundamental wave. The green laser beam emitted outside the nonlinear optical element (101) is reflected by an input-coupling mirror (102) and applied again into the nonlinear optical element (101) in order to form a closed optical path for the fundamental wave. Also, the deep-ultraviolet laser beam emitted outside the nonlinear optical element (101) is reflected by a reflecting mirror (28) other than the input-coupling mirror (102) in order to emit the deep-ultraviolet laser beam from a deep-ultraviolet laser beam-generating section (20).

Abstract: A laser light generating apparatus capable of radiating a laser light of third harmonics of the fundamental light as a continuous light, is disclosed. The apparatus includes a first laser light source L1 employing an Nd:YAG laser as a laser medium as a laser light source radiating the continuous laser light of an infrared wavelength, a second laser light source L2 for resonating a laser light from a laser medium of Nd:YVO4 within a resonator for generating second harmonics, as a laser light source radiating a continuous laser light of a green wavelength, and an external resonator 1 consisting of a set of mirrors. The outgoing lights are combined by additive frequency mixing by a phase-matched non-linear crystal element BBO 10 arranged within the external resonator 1 as the outgoing lights are synchronized and resonated simultaneously within the external resonator.

Abstract: A laser generating apparatus has a plurality of laser resonators and control loops for generating frequency locking signals independently for the respective laser resonators. A control signal generation circuit is provided so as to be common to the control loops. Control signals generated by the control signal generation circuit by frequency division are supplied to the respective control loops, whereby the phases of the laser resonators are locked to each other.

Abstract: A semiconductor light exposure device reducing coherency of laser light to an appropriate value by a simplified structure without producing speckles. The semiconductor light exposure device includes an ultraviolet light generating device, a uniform illumination device having the operation of inducing an optical path length difference and a projection device for projecting the laser light from the uniform illumination device. The ultraviolet light generating device includes an Nd:YAG Q-switch laser unit with a wavelength of 1064 nm, oscillated with a longitudinal single mode, a phase modulation unit or phase-modulating the fundamental laser light outgoing from the Nd:YAG Q-switch laser unit with voltage signals having plural frequency components, and a wavelength conversion unit for converting the wavelength of the fundamental laser light phase-modulated by the phase modulation unit into an ultraviolet laser light with a wavelength of 213 nm as a fifth harmonics.

Abstract: A laser light generating apparatus in which the laser light from a laser light source is intensified by an optical resonator arranged outside the laser light source and outputted after wavelength conversion by a non-linear optical crystal element arranged within the optical resonator. The laser light generating apparatus includes a laser light source for radiating the laser light, an optical resonator for resonating the laser light radiated from the laser light source, a non-linear optical crystal element having an anti-reflection film formed on its laser light incident surface and an aperture for interrupting the light reflected by the non-linear optical crystal element within the optical resonator. The non-linear optical crystal element is arranged in the optical resonator so that a line drawn normal to the laser light incident surface will be obliquely inclined relative to the optical axis of the laser optical resonated within the optical resonator.

Abstract: A semiconductor light exposure device reducing coherency of laser light to an appropriate value by a simplified structure without producing speckles. The semiconductor light exposure device includes an ultraviolet light generating device, a uniform illumination device having the operation of inducing an optical path length difference and a projection device for projecting the laser light from the uniform illumination device. The ultraviolet light generating device includes an Nd:YAG Q-switch laser unit with a wavelength of 1064 nm, oscillated with a longitudinal single mode, a phase modulation unit or phase-modulating the fundamental laser light outgoing from the Nd:YAG Q-switch laser unit with voltage signals having plural frequency components, and a wavelength conversion unit for converting the wavelength of the fundamental laser light phase-modulated by the phase modulation unit into an ultraviolet laser light with a wavelength of 213 nm as a fifth harmonics.

Abstract: A master optical disc recording apparatus in need of only little maintenance and allowing easy optical axis adjustment despite its simplified construction. The master optical disc recording apparatus outputs an outgoing light having a converted wavelength ranging from 0.3 to 0.36 .mu.m by a non-linear optical process of a non-linear optical element enclosed within a laser light generating portion 1. The outgoing light is modulated by a light modulator 3 in accordance with recording information from outside to produce an exposing light which is converged by a recording lens 4 on the master optical disc 7 coated with a photosensitive material. The master optical disc 7, kept in rotation, is scanned with light from the recording lens 4 for writing the recording information. The recording lens 4 includes an automatic focusing mechanism including a bi-acid actuator 5 for servo adjustment.

Abstract: A solid-state laser resonator includes a pair of reflectors 4, 5, a bar-like laser medium 6, a plurality of point laser sources 1, 2 and resonator including a plurality of resonator portions. At least one of the paired reflectors 4, 5 has a curved-surface mirror. The laser medium 6 is interposed between the paired reflectors 4, 5. Laser beams 8 emitted from the point laser sources 1, 2 are passed through one of the paired reflectors 4, 5 and irradiated as pumping lights on one end face of the laser medium 6. The resonators include the pair of reflectors, the laser sources 1, 2 and a plurality of thermal lenses. The thermal lenses are formed within the laser medium 6. The resonators produce output laser beam to produce from the other end face of the laser medium 6 through other one of the reflector 5.

Abstract: A laser light beam generating apparatus includes a laser diode, a laser medium, a non-linear optical crystal element, reflecting mirrors, a deflecting mirror, a temperature-control device and a case. The laser diode emits at least one pumping laser light beam. The laser medium is excited by the pumping laser light beam from the laser diode. The non-linear optical crystal element is arranged in outputted light path of the pumping laser light beam from the laser diode. The reflecting mirrors constitute a resonator with the laser medium and the non-linear optical crystal element. The deflecting mirror deflects the light path of the light beam from the resonator. The temperature-control device controls the temperature of the laser diode and the resonator. The case houses the laser diode, the laser medium, the non-linear optical crystal element, the reflecting mirrors, the deflecting mirror, and the temperature-control device.

Abstract: An optical recording medium, typically an optical disc, has a recording region of a laser medium extending thicknesswise thereof, and a reference region positioned radially inwardly of the recording region for emitting reference light. The recording region has pits and lands formed on a surface thereof as representing recorded information. The pits and lands having respective first surfaces parallel to corresponding second surfaces on an opposite surface of the recording region. The first and second surfaces provide different thicknesses of the recording region. When pumping light emitted from a semiconductor laser, for example, is applied to the recording region, the recording region operates as optical resonators between the first and second surfaces for emitting laser signal light of a variable frequency depending on the recorded information. The optical resonators have respective optical axes extending thicknesswise of the recording region.

Abstract: A laser light generating apparatus of the invention comprises an exciting light source (1) for generating a plurality of exciting laser beams, a laser medium (7) for generating at least two laser beams with radiation of the plurality of exciting laser beams at different positions thereof, reflecting means (8) for reflecting at least a part of the laser beams generated from the laser medium (7) and constructing a laser resonator (5) with thermal lenses (7a) through (7d) formed within the laser medium (7), and phase-compensating means (9) for compensating a phase of a laser beam from the laser resonator (5). Therefore, the laser generating apparatus becomes able to generate a laser beam whose energy is much concentrated within a small divergent angle. Furthermore, it becomes possible to control the laser beam in tracking by changing a phase-compensating amount of the phase-compensating means.

Abstract: A laser beam generating apparatus which is easy to manufacture and simple in adjusting operation. The laser beam generating apparatus comprises a light source having a narrow active layer for generating pumping laser beam, a laser medium for receiving the pumping laser beam to form a heat lens therein and generate a fundamental wave laser beam, a non-linear optical crystal element having a face inclined with respect to an optical axis of the fundamental wave laser beam for receiving the fundamental wave laser beam to generate secondary harmonic laser beam, a quarter wavelength plate for suppressing coupling between two polarization modes of the fundamental wave laser beam, and a pair of planar reflecting means for reflecting the fundamental wave laser beam back into the laser medium. The laser medium, non-linear optical crystal element, quarter length plate and planar reflecting means cooperate to constitute a light resonator.