Abstract: An active gain region sandwiched between a 100% reflective bottom. Bragg mirror and an intermediate partially reflecting Bragg mirror is formed on a lower surface of a supporting substrate, to thereby provide the first (“active”) resonator cavity of a high power coupled cavity surface emitting laser device. The bottom mirror is preferably in direct thermal contact with an external heat sink for maximum heat removal effectiveness. The reflectivity of the intermediate mirror is kept low enough so that laser oscillation within the active gain region will not occur. The substrate is entirely outside the first active resonator cavity to a level sufficient to cause lasing. The substrate is entirely outside the active cavity but is contained within a second (“passive”) resonator cavity defined by the intermediate mirror and a partially reflecting output mirror, where it is subjected to only a fraction of the light intensity that is circulating in the gain region.

Abstract: A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beams at high repetition rates. Applicants have shown substantial improvement in performance with the uses of helium purge as compared to prior art nitrogen purges. In preferred embodiments a stream of helium gas is directed across the face of the grating. In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Abstract: A three-cavity stabilized laser system is disclosed. The laser system includes a laser with rear and front ends surrounding a gain medium. First and second wavelength-selective reflective elements with respective first and second overlapping reflectivity bandwidths are optically coupled to the laser. The wavelength-selective reflective elements are arranged so that the laser system operates stably in the coherence collapse lasing regime.

Abstract: A tunable vertical cavity surface emitting laser (VCSEL) using photonic crystals and an electrostrictive material that includes a hologram with a narrow filter function. Photonic crystals are formed such that the active region of the VCSEL is bounded by the photonic crystals. The photonic crystals have a periodic cavity structure that reflects light of certain wavelengths through the active region of the VCSEL such that laser light at the wavelengths is generated. The periodic cavity structure includes a central defect that does not include any cavities. The single mode is emitted through the central defect. The electrostrictive material that includes a hologram makes the VCSEL tunable because the shape of the electrostrictive material changes when an electric field is applied. The filter function of the hologram thus changes as well in response to the electric field such that the VCSEL is tunable.

Abstract: A system capable of creating multiple beams of light using laterally coupled waveguides. Each beam is of a different central wavelength, capable of being generated on chip and coupled into a single fiber, and emitted from a single outcoupling grating (OCG). The present innovations can be used to create a multiple wavelength source generating multiple signals of different wavelengths simultaneously. The present innovations can also function as a tunable laser source system, capable of generating one of many different wavelength signals at a time. Waveguides are laterally coupled through, for example, evanescent coupling. The degree of coupling is controlled by varying the voltage applied to contacts attached to the waveguides at the coupling region.

Abstract: An optical transmitter includes an external cavity laser array formed in a PLC, a trench-based detector array and an AWG. The external cavity laser is formed using an array of substantially similar laser gain blocks and an array of gratings formed in waveguides connected to the gain blocks. Each grating defines the output wavelength for its corresponding external cavity laser. Each detector of the detector array includes a coupler to cause a portion of a corresponding laser output signal of the laser array to propagate through a first sidewall of a trench and reflect off a second sidewall of the trench to a photodetector. In one embodiment, the photodetector outputs a signal indicative of the power level of the reflected signal, which a controller uses to control the laser array to equalize the power of the laser output signals.

Abstract: The invention relates to the stabilization of semiconductor laser diode sources as they are extensively used in the field of optical communication. Such lasers are mostly employed as so-called pump laser sources for fiber amplifiers, e.g. Erbium-doped fiber amplifiers, and are designed to provide a narrow-bandwidth optical radiation with a stable power output in a given frequency band. To improve the stability of such laser sources compared to prior art designs, a plurality of “external” cavities is provided. In the commonly employed optical fibers for conducting the laser beam, these cavities may be formed by a plurality of appropriately designed Bragg gratings. However, the cavities may as well be formed by other means reflecting a given amount of the energy back to the laser in a desired frequency band, thus effecting the stabilization of the laser's intensity and frequency.

Abstract: A laser diode system is provided. The laser comprises first and second reflective gratings at each end of the laser. The laser further comprises an outcoupling grating between the first and second reflective gratings, wherein the outcoupling grating couples light out of the laser. The reflectors and outcoupling grating each have a unique wide-band reflective spectrum. A first laser cavity exists between the first and second reflective gratings. A second laser cavity exists between the first reflective grating and the outcoupling grating. A third laser cavity exists between the second reflective grating and the outcoupling grating, and a fourth laser cavity exists with in the outcoupling region. The overlap of reflective spectra determine the lasing wavelengths that reach resonance within each cavity. Wavelengths resonant in one cavity are suppressed in the others unless a wavelength is resonant in all cavities. This matching of mode intensities causes the outcoupled beam to be confined to a single wavelength.

Abstract: This invention relates to a continuously wavelength tunable monomode laser source with external cavity comprising a resonant cavity having a reflecting plane face, means for extracting a portion of the luminous flux and a retroreflecting dispersive device, an amplifier wave guide located inside the resonant cavity, means for controlling the retroreflecting dispersive device providing continuous tunability.

Abstract: The present invention is directed to a method and system for conditioning the output signals of an array of surface-emitting lasers with an array of edge-receiving optical devices. Both the array of surface-emitting lasers and the array of edge-receiving optical devices are mounted on an optical bench substrate. The array of edge-receiving optical devices may also be monolithically fabricated on the optical bench substrate. The array of surface-emitting lasers and the array of edge-receiving optical devices are aligned by alignment features and slots, which are fabricated on the optical bench substrate so as to optically couple the array of surface-emitting lasers to the array of edge-receiving optical devices.

Abstract: The optical system includes a stack of lensed, AR-coated laser diode bars and optics to brighten the stack's output. A spatial filter forces each bar to lase in one or a few high-order modes having two strong emission lobes. Radiation in the first lobe is passed to a collimating optic to form a filtered image of each of the lensed diode bars on an associated grating, whose angle then determines the lasing wavelength of that bar. Radiation in the second lobe is directed into an output path where another collimating optic produces an array of spatially separated, collimated beams. The wavelengths set for each beam allow them to be spectrally combined into a single, multi-wavelength, collimated output beam possessing substantially the same cross section and divergence as an individual input beam.

Abstract: An external-cavity laser, suitable for producing a coherent and highly-polarized optical emission, particularly at communication wavelengths, is enabled by a novel wavelength selective element based on a waveguide technology that supports a long-range plasmons polariton mode. These external-cavity lasers leverage the inherent properties of the novel wavelength selective elements, which are materials agnostic, providing easier means for tunability, laser stability, and low cost of fabrication, high output power and a highly polarized output. Tunable versions are also disclosed.

Abstract: A multi-section semiconductor laser diode is disclosed. The laser diode includes a complex-coupled DFB laser section that includes a complex-coupled grating and an active structure for controlling the intensity of oscillating laser light, to oscillate laser light in a single mode, and an external cavity including a phase control section and an amplifier section, the phase control section having a passive waveguide that controls a phase variation of feedback laser light, the amplification section having an active structure that controls the strength of the feedback laser light. Currents are separately provided to the three sections to generate optical pulses with tuning range of tens of GHz. Applications include the clock recovery in the 3R regeneration of the optical communication.

Abstract: To provide a laser apparatus and a laser annealing method with which a crystalline semiconductor film with a larger crystal grain size is obtained and which are low in their running cost. A solid state laser easy to maintenance and high in durability is used as a laser, and laser light emitted therefrom is linearized to increase the throughput and to reduce the production cost as a whole. Further, both the front side and the back side of an amorphous semiconductor film is irradiated with such laser light to obtain the crystalline semiconductor film with a larger crystal grain size.

Abstract: The present invention relates to a laser structure (100) on a semiconductor substrate which comprises a first resonator (110), a second resonator (120) and a third resonator (130). The second resonator (120) and the third resonator (130) are designed as ring resonators and are arranged in at least one common section next to the first resonator (110) or next to the second resonator (120), respectively, substantially at a constant spacing from the first resonator (110) or from the second resonator (120), respectively. As a result, the second resonator (120) is optically coupled to the first resonator (110), and the third resonator (130) is optically coupled to the first resonator (110) via the second resonator (120) or directly, respectively, in such a way that a standing wave with a defined wavelength can form in the first resonator (110).

Abstract: Disclosed is a tunable wavelength semiconductor laser diode which comprises a FP(fabry-parrot) laser diode array for producing at least two light beams, a combiner for combining the light beams output by an end of the laser diode array, a lens for collimating the light beams output by another end thereof, a grating for diffracting the light beams collimated by the lens, and a reflector for reflecting the light beams diffracted by the grating to feed the reflected light beams back to the laser diode array.

Abstract: A tunable external cavity laser equipped with an optical path length compensator for adjusting an optical path length of the cavity, a wavelength selector for selecting an operating wavelength of the light in a single longitudinal mode and a dispersion compensator for compensating a dispersion of the light. In order to achieve mode-hop-free tuning the laser has a synchronizer for synchronizing the optical path length compensator, the wavelength selector and the dispersion compensator to maintain the light in the selected single longitudinal mode while the wavelength selector tunes the operating wavelength. The laser employs a pair of prisms and a wedge filter or a gap filter to perform the functions of the optical path length compensator, the wavelength selector and the dispersion compensator.

Abstract: A tunable optical source comprises a laser diode 105 and an external optical feedback device 135. The feedback device 135 has a waveguiding portion fabricated at least in part out of a glass material having both organic and inorganic components. Control means is provided for controlling the refractive index of the glass material so as to change the wavelength of feedback to the laser diode. The glass material may for example have thermo-optic properties and the control means might then be a heating device for heating the glass material. The feedback device 135 can have more than one portion, a second portion for example having controllable coupling characteristics for coupling optical radiation into or out of the feedback device 135. It also preferably has a portion for controlling optical path length in the feedback device 135.

Abstract: A laser oscillator (10) including a reflective mirror (14) and an output coupler mirror (24). Two gain media (16, 22) are disposed between the reflective mirror (14) and the output coupler mirror (24) and each are pumped with energy to produce laser oscillation between the reflective mirror (14) and the output coupler mirror (24). Each of the two gain media (16, 22) has a focal strength during operation that is formed by thermal and mechanical stress. The laser oscillator (10) also includes a lens system (18) disposed between the two solid state gain media (16, 22) and has a focal strength about equal to or greater than a product of the focal strength of the two media (16, 22). A polarization rotator (20) is also included in the laser oscillator and is disposed between the two gain media (16, 22).

Abstract: A one piece laser assembly including a rod of gain medium with one end-face bonded to a broad end-face on a stack of optical wafers that process light differently and mirrors plated on the remaining exposed end-faces of the rod and the stack of wafers.

Abstract: A laser apparatus in a hermetically sealed container and methods for hermetically sealing the laser. The laser apparatus comprising an external cavity laser and a modulator in a single hermetically sealed enclosure.

Abstract: A three-dimensional photonic crystal add-drop filter apparatus has a three-dimensional photonic crystal, a first waveguide for transmitting light having a frequency within a bandgap of the three-dimensional photonic crystal, and a second waveguide. A resonant cavity couples the light in the first waveguide to the second waveguide for extracting at least one wavelength of the light transmitted in the first waveguide and redirecting the extracted light to the second waveguide. The apparatus has a full three-dimensional bandgap and thus does not require total internal reflection to confine the light as is required in a two-dimensional photonic crystal slab. The waveguides can be made single mode such that only one polarization is allowed to propagate thus avoiding mixing of the two polarizations.

Abstract: Apparatus for frequency conversion of light, the apparatus comprises: a light-emitting device for emitting a light having a first frequency, the light-emitting device being an edge-emitting semiconductor light-emitting diode having an extended waveguide selected such that a fundamental transverse mode of the extended waveguide is characterized by a low beam divergence. The apparatus further comprises a light-reflector, constructed and designed so that the light passes a plurality of times through an external cavity, defined between the light-emitting device and the light-reflector, and provides a feedback for generating a laser light having the first frequency. The apparatus further comprises a non-linear optical crystal positioned in the external cavity and selected so that when the laser light having the first frequency passes a plurality of times through the non-linear optical crystal, the first frequency is converted to a second frequency being different from the first frequency.

Abstract: A wavelength tunable laser light source necessary for a Wavelength Division Multiplexing (WDM)-based optical communication system, and more particularly, a wavelength tunable laser light source for maintaining a stable wavelength without a wavelength locker is provided. The wavelength tunable laser includes an optical fiber and a semiconductor device. The optical fiber can implement multiple reflection peaks. The semiconductor device includes a mode size converter section, a gain section and a DBR mirror section. One facet of the semiconductor device, which is adjacent to the optical fiber, has an antireflection coating layer. Therefore, the wavelength tunable laser based on an optical fiber containing multiple reflection peaks can maintain excellent wavelength stability insensitive to current injection, temperature, and environments without a wavelength locker.

Abstract: A wavelength monitor capable of obtaining an optical detection signal of high quality is proposed. In the wavelength monitor, a light incident surface of an optical filter is disposed with an inclination relative to the light incident direction. With this arrangement, it is possible to make the route of a reflection light that has been reflected from the light incident surface of the optical filter deviate large from the route of an incident light that has been incident to the optical filter. Consequently, the reflected light is prevented from being incident to a semiconductor laser device or optical detectors.

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: The integrated-optics coupling component is designed to cooperate with a transverse multimode power laser diode (2) with semi-conductor to form a transverse multimode power laser. It comprises an input zone (4) connected to at least one output waveguide (6) by at least two adiabatic tapering zones (5). At least two filtering windows (7) form the inputs of the adiabatic tapering zones (5) at the end of a diffraction zone defined by the input zone. Reflecting elements, for example a Bragg grating (12), can be arranged on the output waveguide. An emitting face (3) being antiglare-treated, an extended laser cavity oscillating on a single predetermined mode is thus defined between a reflecting rear face (11) of the laser diode and the reflecting elements (12).

Abstract: A single mode high power vertical cavity surface emitting laser (VCSEL) using photonic crystals. A photonic crystal is included in at least one mirror layer of a VCSEL. The reflectivity of the photonic crystal is dependent on the wavelength and incident angle of the photons. The photonic crystal can be formed such that the VCSEL lases at a single mode. Because a single mode is generated, the aperture of the VCSEL can be enlarged to increase the power that is generated by the VCSEL for that mode. The photonic crystal can be used with/without DBR layers. The photonic crystal, in one example, forms an external cavity.

Abstract: An apparatus for generating a coherent laser beam from an emission of a series of diode lasers, comprising at least one row of source diodes and a system for transforming the primary light emission emitted by the source diodes into secondary coherent light emission, wherein the system for transforming the primary emission into secondary coherent light emission includes a hologram, which comprises an image of an interference pattern of the primary light emission and the secondary coherent light emission, so that when illuminating the hologram with the primary light emission, the hologram reflects the secondary coherent light emission and in that a mirror is provided in the path of the secondary coherent light emission, which reflects at least some of the secondary coherent light emission via the hologram to the diode lasers.

Abstract: A grating-stabilized semiconductor laser comprises a semiconductor laser gain medium, an integrated low-index waveguide, and a waveguide grating segment providing optical feedback for laser oscillation. The laser may be adapted for multi-mode or single-mode operation. A multiple-mode laser may oscillate with reduced power and/or wavelength fluctuations associated with longitudinal mode wavelength shifts, relative to Fabry-Perot lasers lacking gratings. A single-mode laser may include a compensator, wavelength reference, and detector for generating an error signal, and a feedback mechanism for controlling the compensator for maintaining the laser wavelength locked to the reference. The laser may include means for altering, enhancing, tuning, and/or stabilizing the waveguide grating reflectivity spectral profile. The laser may be adapted for optical transverse-coupling to another waveguide.

Abstract: A semiconductor laser includes first and second laser cavities. The first and second cavities share a common optical gain medium and lase at different wavelengths.

Abstract: The inventive rod includes a gain medium having first and second equal length portions sharing a common optical axis and an optical rotator disposed between said first and second portions which optical rotator compensates for birefringence. In an exemplary case, the optical rotator includes first and second waveplates optically coupled to one another and oriented with respect to one another by a predetermined angle, where the first waveplate receives a polarized beam having a first state, and the second waveplate produces the polarized beam having a second state, the first and second states differing from one another by 90°. Multiple rotators can be employed to compensate strongly birefringent rods, each rotator compensating a section of a rod constructed from a plurality of equal length optical gain elements.

Abstract: An optical wavelength converting apparatus includes a first semiconductor laser, a second semiconductor laser, and a wavelength converting element for converting first and second laser light from the first and second semiconductor lasers to sum frequency light. In this apparatus, the first semiconductor laser and the wavelength converting element are arranged so as to establish an external resonator structure in which the first laser light can be put under a resonant condition, and an optical path of the second laser light is so determined that the second laser light can propagate through the wavelength converting element.

Abstract: Optical structures and method for producing tunable waveguide lasers. In one embodiment, a waveguide is defined within a glass substrate doped with a rare-earth element or elements by ion diffusion. Feedback elements such as mirrors or reflection gratings in the waveguide further define a laser-resonator cavity so that laser light is output from the waveguide when pumped optically or otherwise. Means are disclosed for varying the wavelengths reflected by the reflection gratings and varying the effective length of the resonator cavity to thereby tune the laser to a selected wavelength. Apparatus and method for integrating rare-earth doped lasers and optics on glass substrates. The invention includes a laser component formed from a glass substrate doped with a optically active lanthanides species with a plurality of waveguides defined by channels within the substrate.

Abstract: An edge emitting laser that emits a single mode using photonic mirrors. An edge emitting laser includes an active region that is formed between an n-type semiconductor material and a p-type semiconductor material. Photonic mirrors are formed in the laser to define a gain cavity and an external cavity. The gain cavity is bounded by a cleaved facet and a photonic mirror or by a pair of photonic mirrors. The external cavity is bounded by the photonic mirror of the gain cavity and either a cleaved facet or another photonic mirror. The mode emitted by the laser is determined by characteristics of the photonic mirrors, including the periodic cavity structures of the mirrors.

Abstract: A single mode high power vertical cavity surface emitting laser (VCSEL) using photonic crystals. A photonic crystal is included in at least one mirror layer of a VCSEL. The reflectivity of the photonic crystal is dependent on the wavelength and incident angle of the photons. The photonic crystal can be formed such that the VCSEL lases at a single mode. Because a single mode is generated, the aperture of the VCSEL can be enlarged to increase the power that is generated by the VCSEL for that mode. The photonic crystal can be used with/without DBR layers. The photonic crystal, in one example, forms an external cavity.

Abstract: Methods and devices are provided for converting a fundamental wavelength of a fundamental beam generated by a surface-emitting diode laser having a first resonating cavity. According to some embodiments, a first nonlinear crystal disposed in a second resonating cavity external to first resonating cavity converts the fundamental beam to a first output beam having a first output wavelength different from the fundamental wavelength. Some embodiments include a second nonlinear crystal, which may be disposed in the second resonating cavity or in a third resonating cavity, for producing a second output beam having a second output wavelength different from the first output wavelength. In some such embodiments, the second nonlinear crystal converts the wavelength of the first output beam to produce the second output beam. In some embodiments, the second nonlinear crystal interacts with the first output beam and an infrared beam from another laser device to produce the second output beam.

Abstract: A vertical-external-cavity surface-emitting laser (VECSEL) is formed by providing a monolithic portion having a first laser cavity mirror and an active region disposed on the first mirror. The cavity is completed with a second laser cavity mirror, such as a DBR, deposited onto the light-receiving end of an optical device, such as an optical fiber. The DBR-on-fiber-end is mounted with respect to the active region to complete the laser cavity and to provide automatic coupling of the output laser light into the fiber.

Abstract: A multi-frequency light source is disclosed. In one aspect, a multi-frequency light source may comprise a gain region defined by a first and second mirror. The gain region may have a resonant mode. The light source may also have an external cavity defined by a third mirror and the second mirror. The external cavity has plurality of resonant modes, including a plurality of contiguous desired modes of operation. The second mirror may be formed such that the multi-frequency light source operates at the desired modes of the external cavity.

Abstract: An optical device for use in data communication technique is presented. The device comprises a combination of two spaced-apart waveguides and at least two spaced-apart resonator-cavity loops. The resonator-cavity loops are accommodated between the two waveguides and connected to each other through sections of the waveguides in such a manner that the resonator-cavity loops and the waveguide sections create a closed loop compound resonator for storing optical energy of a predetermined frequency range. A control means is used for controlling physical characteristics of the compound resonator to adjust its optical storage characteristics.

Abstract: A wavelength tuning system adjusts an external cavity of a laser about two orthogonal axes for aligning features of a diffractive optic with a third orthogonal axis about which the diffractive optic is pivoted for providing selected wavelength feedback to the laser. A laser mount supports the laser, and a mounting arm supports both the diffractive optic and a reflective optic in a fixed orientation with respect to each other. A flexural member forms at least part of a connection between the mounting arm and the laser mount in a relative orientation for optically coupling the diffractive optic to the laser within the external cavity. The mounting arm is pivoted with respect to the laser mount about the pivot axis by an actuator for varying a wavelength of a diffracted portion of the output beam returned to the laser without significantly varying an angular orientation of the output beam with respect to the laser mount as reflected from the reflective optic.

Abstract: Methods and apparatus for optimizing feedback suppression of optical isolators when used with variable wavelength light sources. The methods comprise positioning an optical isolator in a light beam, and adjusting feedback suppression by the optical isolator according to wavelength of the light beam. Adjusting the feedback suppression may comprise adjusting temperature of the optical isolator or a non-reciprocal rotator associated with the isolator.

Abstract: The present invention is directed to a system and method which utilize an incoherently beam combined (IBC) laser. The IBC laser includes a plurality of emitters with each of the emitters possessing a partially reflective surface on their front facet. The partially reflective surface causes resonant wavelengths to be defined. In certain embodiments, the system and method arrange the external cavity and emitter spacings of the IBC laser such that the center feedback wavelength provided to each emitter is an etalon resonant wavelength. In other embodiments, the range of feedback wavelengths is adapted so that it is greater than the free spectral range (the separation in wavelength space between adjacent etalon resonant wavelengths).

Abstract: A multimode light generating module comprises an optical cavity and a light-receiving element. The optical cavity is constituted by a semiconductor optical amplification element, and an optical fiber having a grating. The optical fiber comprises a grating having an apodized periodic refractive index distribution, and the slope of the reflection spectrum in a longer wavelength region with respect to the peak wavelength &lgr;p is gentler than that in the shorter wavelength region therewith. The grating satisfies the relationship of 0.5 nm>&lgr;0.2−&lgr;p>0.1 nm. Here, &lgr;0.2 is defined by &lgr;0.2h−&lgr;0.21, where &lgr;0.2h is the longer one of two wavelengths exhibiting a relative reflectivity of 0.2 with respect to the maximum reflectivity, and &lgr;0.21 is the shorter one of two wavelengths exhibiting a relative reflectivity of 0.2 with respect to the maximum reflectivity.

Abstract: An optical parametric oscillator (OPO) having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately &rgr;Lcrystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

Abstract: A device is provided, the device comprising a first vertical cavity surface-emitting laser (VCSEL) of a monolithic vertical cavity surface-emitting laser (VCSEL) array, the first vertical cavity surface-emitting laser (VCSEL) being tunable to a first plurality of wavelengths. The device also comprises a second vertical cavity surface-emitting laser (VCSEL) of the monolithic vertical cavity surface-emitting laser (VCSEL) array, the second vertical cavity surface-emitting laser (VCSEL) being tunable to a second plurality of wavelengths, wherein at least one wavelength is in both the first plurality of wavelengths and the second plurality of wavelengths.

Abstract: A laser apparatus capable of emitting laser beams of a plurality of different wavelengths is disclosed.

Abstract: A laser-radiation source includes a laser delivering an output beam, a lens, and an optical arrangement for dividing the output beam into a main beam and an auxiliary beam. The main and auxiliary beams are coupled by the lens into entrance faces of respectively a main optical fiber and an auxiliary optical fiber. The entrance face of the main optical fiber is located on the optical axis of the lens. The entrance face of the auxiliary optical fiber is laterally displaced from the optical axis of the lens.

Abstract: The present invention provides for the coupling of laser diodes into electromagnetic radiation transmitting fibers wherein coupling efficiency is improved by improving the spatial brightness of multi-mode diode lasers as they are coupled into double-clad fibers. A Bragg grating 100 is fabricated into the core 102 of a double-clad fiber 104 coupled to a multi-mode diode laser 106. The output 108 from the multi-mode diode laser 106 is coupled into the core 102 and inner cladding 110 of the double-clad fiber by proximity or by one or more focusing objectives 112. The Bragg grating 100 in the core 102 of the double-clad fiber 104 is written at the wavelength of the multi-mode diode laser 106. The original output 108 from the multi-mode diode laser 106 strikes the Bragg grating 100 which reflects feedback 114 back to the diode laser 106.

Abstract: Microwaves are generated by heterodyning the outputs of two or more optical lasers which have differing central frequencies to produce beat frequencies in the microwave range. One of the beat frequencies is used to modulate the output of at least one of the lasers so as to produce sidebands which differ from the central frequency by an integral number of the sideband frequency. Each laser is connected to one of the other lasers by a weak optical link to optically injection lock the laser to the sideband of the other laser.