Abstract: A monolithic transmitter photonic integrated circuit (TxPIC) chip comprises an array of modulated sources formed on the PIC chip and having different operating wavelengths according to a standardized wavelength grid and providing signal outputs of different wavelengths. Pluralities of wavelength tuning elements are integrated on the chip, one associated with each of the modulated sources. An optical combiner is formed on the PIC chip and the signal outputs of the modulated sources are optically coupled to one or more inputs of the optical combiner and provided as a combined channel signal output from the combiner. The wavelength tuning elements provide for tuning the operating wavelength of the respective modulated sources to be approximate or to be chirped to the standardized wavelength grid. The wavelength tuning elements are temperature changing elements, current and voltage changing elements or bandgap changing elements.

Abstract: A method of operating an array of laser sources integrated as an array in a single monolithic chip where the steps include designing the laser sources to have different target emission wavelengths so that together they form a spectral emission wavelength grid, coupling outputs from the laser sources to an array of gain/loss elements also integrated on the single monolithic chip, one each receiving the output from a respective laser source; and adjusting the outputs with the gain/loss elements so that the power levels across the laser source array are substantially uniform.

Abstract: A wavelength-locked loop servo-control circuit and methodology that enables real time mutual alignment of an electromagnetic signal having a peaked spectrum function including a center wavelength and a wavelength selective device implementing a peaked passband function including a center wavelength, in a system employing electromagnetic waves.

Abstract: A C- and/or L-band booster optical amplifier is utilized in an optical communication system at the output of one or more semiconductor transmitter photonic integrated circuit (TxPIC) chips or the optical combined outputs of multiple semiconductor transmitter photonic integrated circuit (TxPIC) chips employed in an optical communication module, the deployment of integrated semiconductor optical amplifiers (SOAs) on the TxPIC chips can be eliminated. This would reduce both the complexity in designing and fabricating these chips as well as reducing the power consumption of the TxPIC chips. The deployment of such a Tx booster optical amplifier would also take into consideration the nonlinear effects of difficult high loss single mode fiber (SMF) or other fiber type links by allowing a higher power per channel to be achieved compared to the case where channel amplification is attempted solely on the TxPIC chip.

Abstract: A coherent laser beam combining system wherein the output of a single master oscillator is split into a plurality of N signals, and the N signals are electronically modulated at unique frequencies. There is no reference signal and all of the signals are passed through phase adjusters. All N signals are optically amplified, aligned and passed through a beam splitter to split off a small sample that is imaged onto a photodetector. The photodetector output is fed to a signal processor that separates the N signals and produces N phase error signals that drive the N phase adjusters resulting in a high-powered optically coherent output signal.

Abstract: A contact-less high-speed signaling interface and method provide for the communication of high-speed signals across an interface, such as a die-substrate interface or die-die interface. The interface includes a transmission-line structure disposed on a dielectric medium to carry a high-speed forward incident signal, and another transmission-line structure disposed on another dielectric medium and substantially aligned with the other transmission-line structure to generate a coupled high-speed signal in a direction opposite to the incident signal.

Abstract: An optical test system for use in testing fiber optical transmission systems and components comprises a modular construction in a single housing. The modular construction includes a plurality of laser source channels, a MUX, additional optical conditioning devices both upstream and downstream of the MUX, and a master controller for operating the system components in synchrony. The integral housing, together with the modular construction, provides increased structural density that occupies in many instances at least seventy percent less space than is required for other optical test systems. The use of a master controller to drive the system affords expanded system functionality.

Abstract: Laser processing methods, systems and apparatus having a super-modulating power supply (6) or pumping subsystem (5) and high beam quality (i.e., brightness) are disclosed. The methods, systems and apparatus have significant benefits, improved operation characteristics and material processing capability over currently available methods, systems and apparatus. In at least one embodiment, the beam quality of a high power solid state laser (2) is improved in the presence of thermal lensing. High power laser cutting, scribing, and welding results are improved with a combination of modulation and high beam quality while providing for improved processing speeds.

Abstract: An optical semiconductor device comprises a semiconductor laser (11) including a lower clad layer, an active layer (4), and an upper layer formed in this order, an electroabsorptive modulator (12) including the lower clad, a light absorption layer (6), and the upper clad layer formed in this order, and a separation region (13) provided between the semiconductor laser and the electroabsorptive modulator. The upper clad layer extends from the semiconductor laser through the separation region to the electroabsorptive modulator and up to the side of the separation region.

Abstract: In a semiconductor optical modulator of this invention, each quantum-well layer and each barrier layer of a quantum-well structure serving as a light absorption layer are respectively made of In1-X-YGaXAlYN (0?X, Y?1, 0?X+Y?1) and In1-X?-Y?GaX?AlY?N (0?X?, Y??1, 0?X?+Y??1). An electric field is being generated in the light absorption layer by spontaneous polarization.

Abstract: A laser includes a gain medium located in a laser resonator. The gain medium generates plane polarized radiation plane polarized in a first polarization orientation. An electro-optical switch is located in the resonator. When the switch is activated the polarization plane of the laser radiation is rotated to a second orientation after making a forward and a reverse pass through the optical switch. When the switch is deactivated, the polarization orientation of the forward and reverse transmitted laser radiation remains about the same. A polarization selective device is located in the resonator between the electro-optical switch and the gain medium. The polarization selective device is arranged to permit circulation in the resonator of laser radiation in the first polarization orientation, and to restrict circulation of laser radiation in the second polarization orientation. The Gain medium is energized and the switch activated to allow energy to build in the gain medium.

Abstract: A light beam scanning device includes a light source section, a deflector and a reflection type optical system. The light source section is provided with three laser light sources. These laser light sources utilizes different modulation systems depending on corresponding semiconductor lasers. That is, the red-light laser light source and the blue-light laser light source each utilize a direct modulation system and the green-light laser light source utilizes an external modulation system using an external modulator (AOD). Reflecting mirrors and, the deflector and an arcsine mirror, which form the reflection type optical system, are arranged sequentially along an optical path at the side of the light source section from which light is emitted. Accordingly, laser light emitted from the light source section is guided only by the reflection type optical system to a recording material. As a result, no correction for light beams of different wavelengths is required.

Abstract: A laser beam is obtained from a semiconductor laser by a stable emission light amount. A first semiconductor laser is thermally coupled with a second semiconductor laser and driven by a feedback circuit constructed by a photodetector, an I-V converter, and a current generator so as to stabilize the emission light amount. A current I0? having a correlation with a drive current I0 of the 1st laser is outputted from a current mirror circuit. A modulation signal is supplied to a current pull-in type current driving circuit via a multiplier and a linearity compensating circuit and a current I2 according to the modulation signal is extracted from a collector of a transistor. The 2nd laser is driven by a current I1 (I0??I2) and a laser beam modulated by the modulation signal is generated. Since the signal modulation by the 2nd laser is performed without influencing on I0 and the 2nd laser is driven by I0?, the emission light amount is stabilized.

Abstract: A fixed wavelength, external cavity semiconductor laser comprises a semiconductor laser gain medium and an intra-cavity filter having a filter function specifying a frequency of operation of the laser. This distinguishes it from distributed feedback Bragg reflector systems in which the wavelength of operation is dictated by the semiconductor Bragg grating, drive current, and temperature. A cavity length modulation system is further provided that modulates an optical length of the cavity to change the spectral locations of longitudinal modes of the cavity relative to the filter function. One important advantage of the present invention is that it can be deployed without a thermoelectric (TE) cooler. Specifically, the intra-cavity filter material in combination with the cavity length controller, allow a mode of cavity to be located at the filter function.

Abstract: A laser device includes a laser diode, and a controller that superimposes a low-frequency signal on a modulating signal applied to the laser diode. The low-frequency signal has an amplitude that correlates with an amplitude of the modulating signal.

Abstract: A fast, high-swing driver circuit for driving an electro-optical modulator includes an output stage comprising first and second transistors arranged as a differential pair. The collector of the first transistor is coupled to ground, and its base provides the stage's input. The collector of the second transistor is coupled via an impedance to a supply voltage, and provides the stage's output. A reference voltage is provided to the second transistor's base, which is also AC-coupled to ground. A bias generator provides the second transistor's base voltage, and a second differential pair converts a differential input signal to a single-ended output that drives the output stage's input—preferably via a pair of cascaded emitter-follower stages that serve to present a low impedance. A complete electro-optical modulator driver is formed with the addition of a bias-T network at the output stage's output.

Abstract: A method of deploying a passive optical combiner that is a broad bandwidth spectral wavelength combiner for combining the outputs from multiples transmitter photonic integrated circuit (TxPIC) chips and, thereafter, the amplification of the combined channel signals with a booster optical amplifier couple between the passive optical combiner and the fiber transmission link. The booster optical amplifier may be a rear earth fiber amplifier, such as an erbium doped fiber amplifier (EDFA), or one or more semiconductor optical amplifiers (SOAs) on one or more semiconductor chips.

Abstract: A digital reading and/or writing system and method for reading and/or digital data recorded on a digital recording medium. The system includes a first array having a plurality of near-field solid immersion optical lenses and a second array having a plurality organic micro-cavity lasers with the capability of light intensity modulation. The first array being positioned with respect to the second array such that each near-field optical lens of the first array is associated with at least one organic micro-cavity laser in the second array wherein each of the plurality of organic micro-cavity lasers with the capability of light intensity modulation providing light to its associated near-field solid immersion optical lens that is used for reading digital data on the digital recording medium.

Abstract: A method for characterizing tunable semiconductor laser diodes in which the laser is stimulated in a way that discloses the optical properties and tuning current dependency of the individual sections of the laser, separately for each section, and independently of the other sections. A section of the laser is current modulated in order to excite a continuum of modes related to the spectral response of other sections. This process is observed by viewing the overall spectral response at an integration time significantly longer than the modulation time. The spectral positions of the modes and their dependence on the tuning current, are used to determine the tuning characteristic of that particular section. This method substantially reduces the time required for characterization of such lasers in comparison with prior art methods.

Abstract: A laser polarization control apparatus includes a polarization modifying device, such as a liquid crystal variable retarder, and a controller. The polarization modifying device receives a laser beam and modifies the polarization of the laser beam. The controller, which is connected to the polarization modifying device, adjusts an input to the polarization modifying device in order to control modification of the polarization of the laser beam based on alignment of a structure to be processed by the laser beam. For example, the polarization of the laser beam may be rotated to correspond with the alignment of a link in a semiconductor device to be cut by the laser beam. The polarization modifying device is configured for incorporation into a laser processing system that produces the laser beam received by the polarization modifying device and that focuses the laser beam modified by the polarization modifying device onto a workpiece that includes the structure to be processed by the laser beam.

Abstract: An optically-active air-clad fiber (30) includes a core (34, 84) that facilitates doping with an ion optically excitable and having a three-level optical transition when pumped at a first end (28) of an optical cavity (46) by a multimode pump source (72) at a pump wavelength (64) for lasing at a signal wavelength (66) different than the pump wavelength (64) at a second end (29) of the optical cavity (46), the core (34, 84) having a refractive index, wherein the core (34, 84) is transformed from the first end to proximate the second end (29) thereof such that the optically-active fiber (30) is multimode at the pump wavelength proximate to the first end (28), and is single-mode at the signal wavelength proximate to the second end (29). An air-clad (36, 86) surrounds at least one portion of the core (34, 84) and has a lower effective refractive index than the refractive index of the core (34, 84).

Abstract: According to the invention, a laser and a method of operating a laser which can produce multiple pulses from a single laser head is provided. A lasing medium is pumped by pumping source such as laser diodes, lamp and such. A modulator located in the cavity is turned on to induce a loss in the laser cavity sufficient to prevent lasing. A first predetermined amount of energy is stored in the lasing medium while the modulator is turned on due to a creation of a population inversion in the lasing medium in excess of the lasing threshold. The modulator is then turned off for a period of time to allow the lasing medium to provide a first pulse. The modulator is then turned on before the population inversion in the laser medium is depleted completely so that a predetermined amount of energy remains stored in the lasing medium. After the first pulse, the modulator again induces a loss in the cavity sufficient to prevent lasing.

Abstract: A pulsed laser system includes a laser pump, a laser rod, a reflector interposed between the laser pump and the laser rod, through which energy from the laser pump enters the laser rod, an output reflector through which energy is emitted from the laser rod, a switch interposed between the laser rod and the output reflector, and a control device. The switch, when closed, causes energy to be stored in the laser rod and, when opened, allows energy to be emitted from the laser rod during an emission period. The control device allows a primary laser pulse emitted from the laser rod during the emission period to impinge on a workpiece and blocks from the workpiece secondary laser emission occurring during the emission period after emission of the primary pulse. The pulsed laser system is operated over a range of repetition rates, so as to cause laser energy to be emitted during a plurality of emission periods at each repetition rate.

Abstract: An apparatus for providing modulated light, that includes: a VCSEL array for generating an illumination beam from a plurality of emissive elements within the VCSEL array; a linear array of electromechanical grating devices for modulating the illumination beam to provide a plurality of diffracted orders; an obstructing element for blocking at least one of the plurality of diffracted orders; and means for conditioning the illumination beam to provide a suitable aspect ratio for incidence onto the linear array of electromechanical grating devices and/or remove unwanted spatial content.

Abstract: An optical transmitter and/or a constituent electro-optic transducer driver that performs active matching. The transducer driver performs active matching using a voltage step down through one base-emitter bipolar transistor, followed by a step up approach through the base-emitter of another bipolar transistor, thereby allowing for lower supply voltages. Furthermore, the voltage drop across the source resistor is minimal by using an operation amplifier in a feedback configuration, thereby further encouraging operability with low supply voltages. The electro-optic transducer driver is also beneficial in that it has high AC-coupling efficiency of the modulation current to the electro-optic transducer, may operate at high speeds with reduced jitter.

Abstract: Lasers are provided to deliver a wide variety of wavelengths at variable pulse energy. A laser cavity is formed between a first and second reflective surface. A lasing medium is located within cavity which lases at a preselected fundamental frequency. One or more nonlinear crystals are provided in optical communication with the lasing crystal to produce a secondary beam having a different frequency than the fundamental beam. A modulator is provided to control the pulse energy of the secondary beam. Desirably the secondary beam is a harmonic beam for example a second, third, fourth or fifth harmonic beam or a beam provided by an optical parametric oscillator.

Abstract: A semiconductor laser has an antiresonant waveguide (10), which is formed by a layer sequence applied to a substrate (1). The layer sequence has outer waveguide regions (2, 8), reflection layers (3, 7), and a waveguide core (11) with an active layer (5). With this structure, semiconductor lasers with only slight vertical beam divergence and with a large beam cross section can be produced.

Abstract: A method and apparatus for reducing speckle uses polarization averaging. A polarizing beam splitter divides a first polarized laser output into a second polarized laser output and a third polarized laser output. A plurality of mirrors creates an optical path difference between the second and third polarized laser outputs. The optical path difference is at least about a coherence length for the first polarized laser output. The second and third polarized laser outputs are combined into a fourth laser output, which illuminates a depolarizing screen. If a human eye or an optical system having a intensity detector views the depolarizing screen, the eye or the intensity detector will detect reduced speckle, which results from uncorrelated speckle patterns created by the second polarized laser output and the third polarized laser output. A first alternative embodiment of the invention functions without the optical path difference being at least about the coherence length.

Abstract: A laser (126) and an AOM (10) are pulsed at substantially regular and substantially similar constant high repetition rates to provide working laser outputs (40) with variable nonimpingement intervals (50) without sacrificing laser pulse-to-pulse energy stability. When a working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in coincidence with the laser output (24) to transmit it to a target. When no working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in noncoincidence with the laser output (24) so it gets blocked. So the average thermal loading on the AOM (10) remains substantially constant regardless of how randomly the working laser outputs (40) are demanded. The AOM (10) can also be used to control the energy of the working laser output (40) by controlling the power of the RF pulse (38) applied. When the RF power is changed, the RF duration (44) of the RF pulse (38) is modified to maintain the constant average RF power.

Abstract: A device includes a VCSEL, an optical fiber, and a lens. The VCSEL generates optical light signals having a spatial emission pattern based around an axis of emission. Light signals emitted from the VCSEL substantially along or near the axis of emission are known as high speed modulation patterns. Light signals emitted at angles away from the axis of emission are known as slow speed modulation patterns. Slow speed modulation patterns become slower as the angle between the emitted light signals and the axis of emission increase. The lens is selectively positioned between the VCSEL and the optical fiber for focusing the high speed modulation patterns of the light signals on the optical fiber, and the lens substantially does not focus the slow speed modulation patterns of the light signals on the optical fiber.

Abstract: In one embodiment of the present invention, an apparatus operates a control loop for a tunable optical device. A digital reference signal is converted to an analog reference signal and then introduced into the optical path of the tunable optical device. An analog feedback signal, corresponding to the digital reference signal, is recovered from the tunable optical device. The analog feedback signal is converted to a digital feedback signal. The apparatus sends tuning information to the tunable optical device based on analysis of the digital reference signal and the digital feedback signal. In one embodiment, the tuning information is used for wavelength locking of the tunable optical device. In another embodiment, the operation of the control loop is synchronized with another function of the tunable optical device.

Abstract: There is provided a millimeter wave band frequency optical oscillator predicted to be used as a millimeter wave oscillating frequency signal source in a base station of a millimeter wave wireless transmission system. The optical oscillator has a double resonator structure in which a pair of wavelength tunable fiber grating mirrors are inserted into a unilateral fiber-ring laser resonator in order to internally and additionally form a linear laser resonator. The double resonator structure composed of the two stable laser resonators can oscillate laser of two modes. Due to a beat phenomenon occurring between the two modes, received laser is modulated to an ultra-speed frequency of 60 GHz or greater. A variation in the gain within a resonator is induced by a polarization controller using the dependency of laser modes upon polarization. A modulation frequency is consecutively changed from 60 GHz to 80 GHz by controlling the wavelength of light reflected by the fiber grating mirrors.

Abstract: An optical device has a back facet (27) and a front facet (29; 29?) opposite to each other, and includes a laser (23) adapted to emit light essentially perpendicular to said back facet; a modulator (25; 51; 55) having an input end and an output end (35; 53; 57), respectively, and adapted to receive and modulate light emitted from said laser and to output modulated light at said modulator output end; and a window region (33) arranged between said modulator output end and said device front facet, said device being further arranged such that modulated light output from said modulator is transmitted through said window region and is output from said device through said device front facet. The modulator is bent such that the modulated light output from said modulator is propagating essentially in a direction (34), which is angled (?; ?) with respect to the normal (Z; 71) of said device front facet.

Abstract: It is an object of the present invention to provide a driving circuit which can drive a light emitting element in spite of a reduced power supply voltage and which is thus suitable for size reduction. The present invention provides a driving circuit which supplies a bias current to a light emitting element and which carries out modulation on the basis of voltage driving, the driving circuit comprising a boosting circuit that increases a power supply voltage Vcc, a resistance element connected between an output of the boosting circuit and an anode terminal of the light emitting element, and a capacitive element connected to the anode terminal of the light emitting element to supply a modulation signal to the light emitting element for voltage driving.

Abstract: An automatic closed loop power control system is described for simultaneously adjusting an output power and an extinction ratio P1/P0 of a laser diode in order to maintain a desired average output power and a desired extinction ratio. The bias current component of a laser diode drive current is adjusted to compensate for changes in the average output power caused by ambient characteristics such as temperature and aging. Simultaneously, a modulation current component of the laser diode drive current is adjusted to maintain an extinction ratio of the laser diode output signal. The bias current and modulation current adjustments are based on the second order statistics of an average output power of the laser diode and a variance in the power output of the laser diode.

Abstract: Optical components including a laser based on a dielectric waveguide extending along a waveguide axis and having a refractive index cross-section perpendicular to the waveguide axis, the refractive index cross-section supporting an electromagnetic mode having a zero group velocity for a non-zero wavevector along the waveguide axis.

Abstract: A tunable optical local oscillator is used for optical heterodyne signal detection using an electrooptic Mach-Zehnder modulator to produce a rapidly tunable optical signal from a tunable RF frequency generator. A combination of the Mach-Zehnder modulator and optical fibers for providing stimulated Brillouin scattering are used to suppress unwanted signals for providing a spectrally pure optical local oscillator waveform. Suppression of unwanted optical signals, up to 50 dB, generated by the Mach-Zehnder modulator is obtained, resulting in high spectral purity of the optical local oscillator waveform with an extended tuning range of the tunable optical oscillator equal to the operating bandwidth of up to 60 GHz of the Mach-Zehnder modulators.

Abstract: 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.

Abstract: An electronic driver circuit for a directly modulated semiconductor laser has a first circuit for generating a constant current and second circuit for modulating the constant current in dependence on a digital data signal. The modulated current forms a laser current that drives the semiconductor laser. An optimal signal shape of the modulated current is guaranteed to the greatest possible extent, even in the case of high modulation frequencies above one Gbit/s, by way of a third circuit that is connected in parallel with the semiconductor laser. The third circuit acts as an ohmic resistance with a high impedance for direct current and with a low-impedance for alternating current with the modulation frequency.

Abstract: An optical phase detector comprising coupling means for receiving two optical inputs and for producing two combined optical outputs, means for detecting the two combined optical outputs and producing two corresponding electrical signals, and means for measuring the difference between the two electrical signals and generating an output difference signal which may be used to provide an indication of the phase difference between the two optical inputs. The optical phase detector comprises a voltage-tuneable electro-optic phase modulator for modulating the phase of an optical input to the optical phase detector to provide a linearized response. In this arrangement the output difference signal may be maintained at a constant level by varying the voltage applied to the electro-optic phase modulator, the applied voltage providing an indication of the phase difference between the two optical inputs. Applications include frequency discriminators, various sensors, and a laser stabilization apparatus.

Abstract: According to the present invention, an optical transmitting system, which enables a precise control of the power and the extinction ratio of the optical output without a small amount of the preset data, will be provided. The system comprises a laser module and a control system that supplies a bias current and a modulation current to the laser module. In the present invention, one of the bias current and the modulation current of the semiconductor laser in the laser module is varied to maintain the power and the extinction ratio of the optical output, and the other of the bias current and the modulation current is calculated based on the specific function. Only coefficients of the specific function are stored in the control system. Therefore, the present invention does not need a large size of the storage in which both the bias current and the modulation current are stored as a table.

Abstract: An optical device including strained and non-strained regions along an optical medium. In one aspect of the present invention, strain-inducing material disposed proximate to the optical medium induces one or more perturbations of a refractive index along the optical medium to selectively reflect an optical beam directed through the optical medium having a first center wavelength back out a first end of an optical path as remaining wavelengths of light are propagated through a second end. In another embodiment, an optical device may include a strained region disposed in a non-strained region so that one or more perturbations of the refractive index compensates for birefringence of an optical beam directed through the optical medium.

Abstract: The present invention discusses a modulation method and apparatus for modulating an extended-cavity laser (211). The method and apparatus (200-203) entails the use of each pulse in an input modulating pulse train as the trigger for the generation of a brief or “notch” pulse, i.e. a pulse that briefly diminishes the normal drive current. Each “notch” pulse is used to drive the semiconduct (211) embedded in an extended cavity with a current that flows opposite to its normal drive current. This serves to diminish the inverted charge-carrier population essential to lasing action, so the laser output falls sharply in a form of amplitude modulation. The invention also discloses a simple, miniaturized means (372, 352, 312) of micropositioning, based on the differential rotation of nested conical plugs, that can serve to couple the semiconductor laser to the cavity.

Abstract: A method for calculating the beam quality and output wavelength spectrum of a photonic crystal distributed feedback laser includes the steps of calculating at least two coupling coefficients and forming a characteristic matrix; repeating the following steps at spaced increments of time until a steady state solution is reached: repeating the following steps for one of the incremental cavity lengths: calculating a gain change and a modal refractive index change for the laser waveguide structure for one incremental stripe width; calculating a spontaneous emission term for the gain change; calculating a gain roll-off term for the gain change; applying the gain change, the modal refractive index change, the spontaneous emission term, and the gain roll-off term to at least two forward-propagating beams and at least two backward-propagating beams for the one incremental stripe width; performing a Fourier transformation with respect to the one incremental stripe width to yield a plurality of diffraction terms; adding

Abstract: “This invention offer optical modulator module with fulfilling the effective and the stable optical modulation, which stabilizes the emission of semiconductor and control the shift of optic axis between the optical component by the temperature change and so on, when using the semiconductor laser. Peculiarly, the optical modulator module includes, in same package, the semiconductor laser (27) as light source, the optical modulation device (28) that has optical waveguide on the surface of the chip made by the element of the electro-optical effect, and the polarization rotating element (40) between said semiconductor laser and said optical modulation device, for bringing plane of polarization of light from said semiconductor laser (27) to optimum plane of polarization in waveguide of the said optical modulation device in line and blocking the returning light from said optical modulation device to said semiconductor laser.

Abstract: Techniques and designs for tunable and dynamically stabilized a laser wavelength in various lasers, including fiber lasers and actively mode-locked lasers. In an actively mode-locked laser, a dynamic wavelength tuning control and a dynamic cavity length control are implemented to maintain mode locking during tuning of the laser wavelength.

Abstract: A laser (126) and an AOM (10) are pulsed at substantially regular and substantially similar constant high repetition rates to provide working laser outputs (40) with variable nonimpingement intervals (50) without sacrificing laser pulse-to-pulse energy stability. When a working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in coincidence with the laser output (24) to transmit it to a target. When no working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in noncoincidence with the laser output (24) so it gets blocked. So the average thermal loading on the AOM (10) remains substantially constant regardless of how randomly the working laser outputs (40) are demanded. The AOM (10) can also be used to control the energy of the working laser output (40) by controlling the power of the RF pulse (38) applied. When the RF power is changed, the RF duration (44) of the RF pulse (38) is modified to maintain the constant average RF power.

Abstract: A method and apparatus are provided for generating short (e.g., picosecond) pulses using a 2 section 1553 nm DBR laser without gain switching nor external modulation. The center wavelength of the DBR section is modulated at 0.5 GHz to generate a constant amplitude frequency modulated optical wave Large group velocity dispersion is then applied with a chirped fiber Bragg grating to convert the FM signal to a pulse stream.

Abstract: A pulsed laser system includes a laser pump, a laser rod, a reflector interposed between the laser pump and the laser rod, through which energy from the laser pump enters the laser rod, an output reflector through which energy is emitted from the laser rod, a switch interposed between the laser rod and the output reflector, and a control device. The switch, when closed, causes energy to be stored in the laser rod and, when opened, allows energy to be emitted from the laser rod during an emission period. The control device allows a primary laser pulse emitted from the laser rod during the emission period to impinge on a workpiece and blocks from the workpiece secondary laser emission occurring during the emission period after emission of the primary pulse. The pulsed laser system is operated over a range of repetition rates, so as to cause laser energy to be emitted during a plurality of emission periods at each repetition rate.

Abstract: A narrow-linewidth high-power single-frequency laser is realized by pumping a laser cavity with a pair of polarized single-mode pump lasers that are driven below their respective “micro-kink” regions and combined with a polarized beam combiner. The pump lasers emit at the same wavelength and include a length of polarization-maintaining (PM) fiber to maintain the polarization of the respective pumps. The laser cavity is selected from microchip, fiber and waveguide devices and is provided with optical feedback. This laser is capable of producing a stable high-power single-mode signal with a very narrow linewidth, e.g. less than 10 kHz and preferably less than 3 kHz.