Abstract: Laser marking system and method are provided. A laser source is configured to supply a laser beam having a first optical intensity level and a respective beam cross-section. A spatial light modulator (SLM) is optically coupled to the laser source to receive the laser beam. The SLM is controlled to generate an output laser beam with an optical pattern containing a data code matrix across the beam cross-section. An optical amplifier is coupled to the SLM to receive the laser beam from the SLM and generate an amplified laser beam containing the same data code matrix as generated by the SLM. The amplified laser beam has a second optical intensity level higher relative to the first intensity level and is selectable to either ablatively or non-ablatively mark a target object with the data code matrix.

Abstract: An optical transmitter with an external modulator includes a light-emitting unit emitting a continuous wave light, a modulation unit modulating the continuous wave light in accordance with an electric signal, a first terminal applying a first positive voltage to a cathode of the light-emitting unit and a cathode of the modulation unit, a second terminal applying a second positive voltage of a constant value to an anode of the light-emitting unit, and a third terminal applying a third positive voltage with the electric signal to an anode of the modulation unit. The second positive voltage is set to a value higher than the first positive voltage, and the third positive voltage is set to a value lower than the first positive voltage.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: An optical signal is produced from a direct modulation resonant cavity device, such as directly-modulated diode laser having an electrode divided into multiple sections. Each section is driven with an electrical waveform such that a time delay is introduced between sections so as to ensure that the different sections reach their peaks at slightly different times.

Abstract: A method of controlling a pulse output in a master oscillator-power amplifier type fiber pulse laser apparatus including a master oscillator unit and a power amplifier unit connected to the master oscillator unit is provided. The method includes starting the master oscillator unit before starting the power amplifier unit.

Abstract: According to one embodiment of the present invention, a method of operating a laser source is provided. The laser source comprises a laser configured to generate an optical signal, and a polarization split and delay unit that is coupled to the optical signal. The polarization split and delay unit is configured to split the optical signal into a first and second orthogonally polarized component, create an optical path difference ?L between the first and second orthogonally polarized components and combine the first and second orthogonally polarized components into a combined signal. The method comprises modulating the optical signal by applying a wavelength modulation signal to the laser such that the modulated optical signal comprises at least a first wavelength ?1 and a second wavelength ?2, wherein the first wavelength ?1 and the second wavelength ?2 are separated by a wavelength difference ??.

Abstract: Particular embodiments of the present invention relate generally to semiconductor lasers and laser projections systems and, more particularly, to schemes for controlling semiconductor lasers. According to one embodiment of the present invention, a laser having a gain section, a phase section and a wavelength selective section is configured for optical emission of encoded data. The optical emission is shifted across a plurality of laser cavity modes by applying a quasi-periodic phase shifting signal I/V? to the phase section of the semiconductor laser. The amplitude of the quasi-periodic signal transitions periodically between a maximum drive level and a minimum drive level at a frequency that varies randomly over time.

Abstract: An optical module is configured with a combination of a single-mode oscillating light source and an optical filter. In this optical module, the single-mode oscillating light source outputs a single-mode, frequency-modulated signal. Further, the optical filter converts the frequency modulation to an amplitude modulation. And, the single-mode oscillating light source and the optical filter are packaged without active alignment on the same substrate. Accordingly, it is possible to realize an optical module in a simple and low-cost configuration by packaging the single-mode oscillating light source and the optical filter by passive alignment, without active alignment, on the same substrate, and by using a simple optical filter such as a waveguide ring resonator, which converts a frequency modulation to an amplitude modulation.

Abstract: A tunable laser is provided, including: a multiple ring resonator that is formed by coupling ring resonant elements having different optical path length from each other; an input/output-side waveguide connected to one of the ring resonant elements; a reflection-side wave guide connected to another one of the ring resonant elements; a PLC substrate on which the multiple ring resonator, the input/output side waveguide, and the reflection-side waveguide are formed; a high reflection film provided to the reflection-side waveguide; an SOA connected to the input/output-side waveguide; film heaters and a phase control region of the SOA for changing the resonant wavelength of the multiple ring resonator; and a light-receiving element for detecting the resonant wavelength of the multiple ring resonator in a thru port of a directional coupler.

Abstract: A pulse width modulation signal generating device which generates a pulse width modulation signal for modulating laser beam according to image data includes: a cycle signal output circuit which outputs a cycle signal having a cycle corresponding to a drawing rate for drawing the image data by the laser beam; and a pulse width modulation circuit which receives supply of the image data and the cycle signal and modulates a pulse wave having a cycle determined by the cycle signal by changing duty ratio of the pulse wave based on the image data to produce the pulse width modulation signal.

Abstract: A laser provides a cavity with complementary wavelength-dependent delay elements to provide the same optical length but time-staggered light paths for different colors. This provides the ability to individually control multiple narrow bands of colors each in a separate time division window.

Abstract: A device contains at least one wavelength-tunable multilayer interference reflector controlled by an applied voltage and at least one cavity. The stopband edge wavelength of the wavelength-tunable multilayer interference reflector is preferably electrooptically tuned using the quantum confined Stark effect in the vicinity of the cavity mode (or a composite cavity mode), resulting in a modulated transmittance of the multilayer interference reflector. A light-emitting medium is preferably introduced in the cavity or in one of the cavities permitting the optoelectronic device to work as an intensity-modulated light-emitting diode or diode laser by applying an injection current. The device preferably contains at least three electric contacts to apply forward or reverse bias and may operate as a vertical cavity surface-emitting light emitter or modulator or as an edge-emitting light emitter or modulator.

Abstract: A modulated diode-laser provides a first sequence of optical pulses. The first sequence of optical pulses is further modulated to provide a second sequence of optical pulses. Pulses in the second sequence have a shorter duration than pulses in the first sequence.

Abstract: A light pulse conditioning apparatus has at least first and second curved reflective surfaces that share a common focus and a light-redirecting element disposed between the first and second curved reflective surfaces to redirect at least a portion of an incident light beam toward the second curved reflective surface as a delayed beam portion. A beam-shifting compensating element is disposed between the first curved reflective surface and the light-redirecting element and in the path of the delayed beam portion, for shifting the optical path of the delayed beam portion as it returns toward the light-redirecting element.

Abstract: A dual output laser source provided on a substrate outputs light from a first and second output. A portion of the light generated by the laser is supplied to a first modulator via the first output. A second portion of the light generated by the laser is supplied to a second modulator via the second output. The first modulator is provided on the substrate and generates a first modulated signal. The second modulator is also provided on the substrate and generates a second modulated signal. Each output of the laser is used to provide continuous wave light sources to components on photonic integrated circuit.

Abstract: A transportable electronic cassette and an image reading device carry out communication by laser light between themselves, with the separation distance to the casing of the opposing device detected by separation distance sensors provided respectively to the electronic cassette and the image reading device. The value of the separation distance detected is monitored to see whether or not the separation distance exceeds a reference value of the detected value at the start of communication by a specific value or more. Conclusion can be made that there has been a relatively large change in the relative position of the electronic cassette and the image reading device if the detected value of the separation distance becomes greater than the reference value by the specific value or more, and consequently emission is halted of the laser light from the electronic cassette and the image reading device.

Abstract: A transmissive active channel element is provided in each signal channel of a monolithic multi-channel TxPIC where each channel also includes a modulated source. The active channel element functions both as a power control element for both monitoring and regulating the output channel signal level of each signal channel and as a modulator for channel wavelength tagging or labeling to provide for wavelength locking the modulated sources. The power regulating function is also employed to control the channel signal power outputs of each channel to be uniform across the channel signal array. All of these functions are carried out by a feedback loop utilizing digital signal processing.

Abstract: A laser processes a workpiece with laser pulses delivered at random time intervals and at substantially constant energy levels by characterizing the laser cavity discharge behavior and utilizing that information for adjusting dummy pulse time periods to compensate for the energy errors. Dummy pulses are laser pulses that are blocked from reaching a workpiece. A second way for providing constant pulse energies employs an AOM for varying amounts of laser energy passed to the workpiece. A third way of providing constant pulse energies entails extending the pulse period of selected pulses to allow additional laser cavity charging time whenever a dummy pulse is initiated.

Abstract: A mode-locked laser employs a light-wavelength-dependent, path-length adjuster to provide different path-lengths for multiple light frequencies and dual modulation frequencies selecting multiple modes with different wavelengths. The result is a single cavity laser producing mode-locked light outputs at defined different frequencies. Tuning of each frequency may be obtained by changing the laser modulation frequencies.

Abstract: Disclosed is a semiconductor laser in which the substrate comprises at least three independent functional sections in the direction of light wave propagation, said functional sections serving different functions and being individually triggered by means of electrodes via electrode leads. An intensification zone, a grid zone, and a phase adjustment zone are provided as functional sections. The light wave is optically intensified in the intensification zone while the phase of the advancing and returning wave is adjusted in the phase adjustment zone. The grid zone is used for selecting the wavelength and adjusting the intensity of coupling between the intensification zone and the phase adjustment zone.

Abstract: A light source device generates irradiation light that is irradiated onto a predetermined face, the light source device including: a laser light source that emits laser light; a diffractive optical element that diffracts the laser light; a diffusion optical element that has an incidence face into which the laser light is incident and a light emission face from which the laser light from the incidence face is emitted, and that diffuses the laser light; and unit structures that are two-dimensionally arrayed on at least one of the incidence face and the light emission face of the diffusion optical element, and that cause the light which is perpendicularly incident into the diffusion optical element to refract at one time, and then emit this light toward the predetermined face.

Abstract: A Vertical-Cavity Surface-Emitting Laser (VCSEL) is disclosed, comprising an optical cavity bounded by a top mirror and a bottom mirror, wherein the top mirror has multiple layers of alternating refractive index, of which the bottom three or more layers of the top mirror are deep oxidation layers having an increased oxidation length, a light emitting active region between the top mirror and the bottom mirror, and an aperture with tapered edges between the active region and the top mirror, wherein the aperture has a thickness, a taper length, an oxide aperture length, a taper angle, and an aperture opening diameter designed to reduce an optical mode's diameter without significantly increasing the optical mode's round trip scattering loss.

Abstract: Metamaterial structures are taught which provide for the modulation of terahertz frequency signals. Each element within an array of metamaterial (MM) elements comprises multiple loops and at least one gap. The MM elements may comprise resonators with conductive loops and insulated gaps, or the inverse in which insulated loops are present with conductive gaps; each providing useful transmissive control properties. The metamaterial elements are fabricated on a semiconducting substrate configured with a means of enhancing or depleting electrons from near the gaps of the MM elements. An on to off transmissivity ratio of about 0.5 is achieved with this approach. Embodiments are described in which the MM elements incorporated within a Quantum Cascade Laser (QCL) to provide surface emitting (SE) properties.

Abstract: A laser light source includes a fundamental laser generator that generates a fundamental laser light, a wavelength conversion element that is made of a ferroelectric crystal with a periodically poled structure and converts the fundamental laser light to a laser light having a different wavelength, a holding member that holds at least a part of an element surface of the wavelength conversion element that crosses a polarization direction of the periodically poled structure, and an insulation layer that is provided between the holding member and the element surface. Electric resistivity of the insulation layer is 1×108 ?·cm or higher.

Abstract: A display system includes a coherent light source that can emit a coherent light beam, an optical component that can direct the coherent light beam to a spatial light modulator, a transport mechanism that can move the optical component to produce a movement in the coherent light beam, and a spatial light modulator having a two-dimensional array of mirrors each configured to selectively reflect the coherent light beam either toward a screen surface or away from the screen surface to form a display pixel on the screen surface. A display image is formed on the display screen by display pixels produced by the mirrors that reflect the coherent light beam toward the screen surface.

Abstract: Photonic integrated circuits on silicon are disclosed. By bonding a wafer of compound semiconductor material as an active region to silicon and removing the substrate, the lasers, amplifiers, modulators, and other devices can be processed using standard photolithographic techniques on the silicon substrate. A silicon laser intermixed integrated device in accordance with one or more embodiments of the present invention comprises a silicon-on-insulator substrate, comprising at least one waveguide in a top surface, and a compound semiconductor substrate comprising a gain layer, the compound semiconductor substrate being subjected to a quantum well intermixing process, wherein the upper surface of the compound semiconductor substrate is bonded to the top surface of the silicon-on-insulator substrate.

Abstract: A communication system (20) includes a transmitter (22) with (i) a transmitter photonic crystal (30) having a waveguide (40) and multiple cavities (42, 44, and 46) spaced along the waveguide (40); (ii) a light source (32); and (iii) a controller (34) that controls the cavities (42, 44, and 46) to translate multiple electronic data bits to optical data bits simultaneously in respective cavities (42, 44, and 46) illuminated by the light source (32). A corresponding receiver (24) includes a receiver photonic crystal (92) having a data/key waveguide (104) for receiving a data/key signal and a latch waveguide (106) for receiving a latch signal. The photonic crystal (92) also includes data readout cavities (110, 112, 114, and 116) and lock cavities (160, 162, and 164) adapted to compare the key bits to respective lock bits.

Abstract: A method of stabilising a laser in order to maintain the laser in SLM operation is disclosed. The resonator cavity of the laser is modulated by a modulation signal applied to a piezo-electric transducer 10 coupled to the output coupler 2 of the laser. The modulation signal is also multiplied by a signal indicative of the energy of the laser radiation within the resonator cavity. The product of these two signals is then low-pass filtered to provide an error signal which is additionally applied to the piezo-electric transducer 10 so as to further vary the optical length of the resonator cavity.

Abstract: A semiconductor optical device has a semiconductor laser portion and a modulator portion which have different mesa structures. The mesa structure of the semiconductor laser portion is a ridge waveguide structure which has air around the mesa. The mesa structure of the modulator portion is a planarized ridge waveguide structure which has an organic insulator buried around the mesa.

Abstract: A tunable pulsed laser includes a seed source and an optical circulator. The optical circulator includes at least a first port coupled to the seed source, a second port, and a third port. The laser also includes an amplitude modulator characterized by a first optical side and a second optical side. The first optical side is coupled to the second port of the optical circulator. The laser further includes a first optical amplifier characterized by an input end and a reflective end. The input end is optically coupled to the second side of the amplitude modulator. The laser additionally includes a tap coupler optically coupled to the amplitude modulator and characterized by a pre-determined split ratio. Moreover, the laser includes a first photo-detector optically coupled to the tap coupler and adapted to receive a portion of the seed signal transmitted through the amplitude modulator and to generate an output signal.

Abstract: A laser and monitoring system is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal. In yet another aspect of the present invention, a multiphoton intrapulse interference phase scan (hereinafter “MIIPS”) method is used to characterize the spectral phase of femtosecond laser pulses and to correct them. A further aspect of the system of the present invention is employed to monitor environmental chemicals and biological agents, including toxins, explosives, and diseases.

Abstract: A photonic semiconductor device and method are provided that ensure that the surface of the device upon completion of the SAG process is planar, or at least substantially planar, such that performance of the subsequent processes is facilitated, thereby enabling higher manufacturing yield to be achieved. A photonic semiconductor device and method are also provided that ensure that the isolation region of the device will have high resistance and low capacitance, without requiring the placement of a thick dielectric material beneath each of the contact pads. Eliminating the need to place thick dielectric materials underneath the contact pads eliminates the risk that the contact pads will peel away from the assembly.

Abstract: In an optical amplifier according to the present invention, a change signal from a change signal source is fed into a light source or a drive circuit. The wavelength of light outputted from the light source is changed based on the change signal. The wavelength-changed output light from the light source is outputted as pumping light from a pumping light generator to be supplied backwardly via an optical multiplexer/demultiplexer into an optical fiber. Signal light is Raman-amplified in the optical fiber with the supply of the pumping light.

Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: The present invention is to provide an LD-driver that enables to adjust the waveform of the driving current to the LD even the driver is constituted with a current controlled device such as bipolar transistor. The LD-driver of the invention provides a plurality of modulation current sources each having a function to set the amplitude, the phase and the pulse width of the current output independently. The LD is provided with the modulation current superposed with each current derived from respective current sources.

Abstract: A control system and apparatus for use with an ultra-fast laser is provided. In another aspect of the present invention, the apparatus includes a laser, pulse shaper, detection device and control system. A multiphoton intrapulse interference method is used to characterize the spectral phase of laser pulses and to compensate for any distortions in an additional aspect of the present invention. In another aspect of the present invention, a system employs multiphoton intrapulse interference phase scan. Furthermore, another aspect of the present invention locates a pulse shaper and/or MIIPS unit between a spectral dispersion point in a laser oscillator and an output of a laser amplifier.

Abstract: A beam of charged particles (e.g., an electron beam) from a charged particle source can be selectively applied to a pair of electrodes. For example, the charged particles can be electrons that are directed toward a first electrode when the charge difference between the electrodes is in one state and directed toward the second electrode when the charge difference between the electrodes is in another state. The electrodes are configured so that the beam of charged particles oscillates between the first and second electrodes.

Abstract: A light source mode alignment device and method and a passive optical network system are provided. The device includes a laser and a temperature control unit connected to each other and further includes a signal processing unit. The laser converts an incident light into a current signal. The current signal is amplified and converted into a voltage signal via a transimpedance amplifier. Together with a modulation signal generated by the signal processing unit, the voltage signal adjusts a bias voltage of the temperature control unit.

Abstract: An optical signal generator is configured with an associated control system and driver configured to reduce speckle. Speckle reduction occurs by pulsing the drive signal between a first current level and a second current level. These pulses force the optical signal generator to introduce oscillations into the optical signal. The coherence of the emitted light is reduced during the period of oscillations in the optical signal, which reduces speckle. In one embodiment, the pulsing of the drive signal brings the drive signal down to a level near or below threshold, which in turn intermittently turns off the optical signal output. Returning the optical signal to a desired optical output intensity introduces the speckle reducing oscillation. The pulse frequency, and duty cycle is controlled by a duty cycle control signal to modulate overall optical power and adjust amount of despeckle.

Abstract: A method of combining beams from a plurality of laser resonators includes frequency modulating the output of each of the lasers with one or more of the lasers frequency modulated out-of-phase with the others. The frequency modulated beams are directed along parallel spaced-apart paths and overlap in a plane along the paths to form a combined beam having a flat-topped intensity distribution.

Abstract: There has been a problem that interference noise called speckle noise occurs in a two-dimensional image display device using laser, and there is no applicable green light source although the speckle noise can be reduced by using a multi-wavelength light source. The present invention adopts a Yb-doped clad pump fiber (103) which is a rare-earth-doped fiber as a laser activation substance, whereby a peak of a fluorescence spectrum can be significantly increased as compared with a case of using an oxide crystal, and a variation width of an oscillation wavelength can be increased. Further, since the rare-earth-doped fiber is used as a fiber amplifier without providing laser mirrors at both ends thereof, control for a resonator length, which has been required in a conventional device (wherein an oxide crystal is used as a laser medium), is dispensed with, and thereby high-speed wavelength control is achieved, resulting in reduction in speckle noise when it is mounted on a two-dimensional image display device.

Abstract: A directly modulated distributed feedback (DFB) laser with improved optical field uniformity and mode stability may include a laser cavity and a distributed reflector and/or external reflectors. The distributed reflector may be a Bragg grating and may extend asymmetrically over a only portion of the laser cavity. The external reflectors may themselves be distributed Bragg reflectors and may have unequal reflectances. Optical field uniformity may be improved by adjusting the length and/or position of the distributed reflector in the laser cavity. Optical field uniformity may be improved by adjusting a coupling strength parameter, which is a function of a coupling coefficient, ?, and the length of the distributed reflector.

Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: A tunable laser has a first optical element spaced apart from a second optical element to form a laser cavity of fixed length there between. An optical gain medium is in at least part of the laser cavity A third optical element is selectively spaced apart from and facing the first optical element or is selectively spaced apart from and facing the second optical element.

Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: RF receivers based on whispering gallery mode resonators.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A semiconductor laser device has an active layer which is divided into two regions in the direction of a resonator, i.e., a light-amplifying region and a saturable absorber region. The light-amplifying region and the saturable absorber region are produced to allow the semiconductor laser device to be in a bistable state. For the light-amplifying region and the saturable absorber region respectively, p-electrodes are separately and independently formed. N-electrodes are provided in relation to the p-electrodes. From one of the p-electrodes, a current which is modulated with noise added thereto is injected.

Abstract: A tunable pulsed laser source comprising a seed source adapted to generate a seed signal and an optical circulator. The optical circulator includes a first port coupled to the seed source, a second port, and a third port. The laser source also includes an amplitude modulator characterized by a first side and a second side. The first side is coupled to the second port of the optical circulator. The laser source further includes a first optical amplifier characterized by an input end and a reflective end including a spectral-domain reflectance filter. The input end is coupled to the second side of the amplitude modulator. Moreover, the laser source includes a second optical amplifier coupled to the third port of the optical circulator.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.