Abstract: The transmission system may include: an optical path adjustment device configured to substantially unify optical paths of a first pre-pulse laser beam and a second pre-pulse laser beam; an optical path separation device configured to separate the optical paths of the substantially unified first pre-pulse laser beam and the second pre-pulse laser beam to an optical path for the first pre-pulse laser beam and an optical path for the second pre-pulse laser beam; a first beam adjustment device disposed on the optical path for the first pre-pulse laser beam separated by the optical path separation device and configured to adjust a beam parameter of the first pre-pulse laser beam; and a second beam adjustment device disposed on the optical path for the second pre-pulse laser beam separated by the optical path separation device and configured to adjust a beam parameter of the second pre-pulse laser beam.

Abstract: A system uses optical signals to monitor real world inputs and convert them to electrical signals for conventional indication and control systems. Optical signals see use where electrical signals cannot and improve reliability of existing control systems. Optical loops extend to peripheral devices which process the light into discrete or analog light signals. A receiving circuit interprets that signal and converts it to a useable electrical signal of discrete or analog form. The system operates within a range of light wavelength from at least as low as 399 nm up to at least as high as 1801 nm. The system replaces electrical conductors for input cards of Programmable Logic Controller systems. The optical sensing devices withstand electrical surges and immersion into water, do not generate electrical noise, allow for maintenance without shock hazard, and lack susceptibility to electrical or magnetic phenomenon.

Abstract: A laser resonator includes an active material, which amplifies light associated with an optical gain of the resonator, and passive materials disposed in proximity with the active material. The resonator oscillates over one or more optical modes, each of which corresponds to a particular spatial energy distribution and resonant frequency. Based on a characteristic of the passive materials, for the particular spatial energy distribution corresponding to at least one of the optical modes, a preponderant portion of optical energy is distributed apart from the active material. The passive materials may include a low loss material, which stores the preponderant optical energy portion distributed apart from the active material, and a buffer material disposed between the low loss material and the active material, which controls a ratio of the optical energy stored in the low loss material to a portion of the optical energy in the active material.

Abstract: Provided is a butt-jointed (BJ) semiconductor integrated optical device having a high manufacturing yield. A semiconductor integrated optical device, which is configured such that, on a semiconductor substrate, a first semiconductor optical element including an active layer and a second semiconductor optical element including a waveguide layer are butt-jointed to each other with their optical axes being aligned with each other, includes: a semiconductor regrowth layer including at least one of a diffraction grating layer or an etching stop layer, which is formed by one epitaxial growth across an entire surface above the active layer and the waveguide layer; and a cladding layer formed above the semiconductor regrowth layer.

Abstract: An electro-optical distance measuring device includes a laser driver for a laser diode for emitting laser light pulses. The measuring device further includes a laser diode voltage supply having a cascade of at least two voltage regulators, each of which provides an output voltage at a level below a laser threshold voltage of the laser diode. By changing from a first to a second switching position of an electronic switching element of the measuring device, one of the laser light pulses can be emitted and, in the steady-state first and the steady-state second switching positions, no laser light is emitted.

Abstract: An optical network unit (ONU) includes an optical transceiver module, a switch, a detecting module, and an ONU chip. The switch is electronically coupled between the optical transceiver module and a power supply. The detecting module is electronically coupled between the switch and the power supply. The detecting module includes a sensor, an amplifier, and a comparator. The sensor is electronically coupled between the power supply and the switch to sense a driving current output from the power supply to the optical transceiver module and output a voltage signal to the amplifier, the amplifier amplifies the voltage signal and outputs an amplified voltage signal to the comparator, the comparator compares the amplified voltage signal with a predetermined voltage signal and outputs a comparison result. The ONU chip controls the switch to connect/disconnect the electrical connection between the optical transceiver module and the power supply according to the comparison result.

Abstract: An architecture for current driver circuitry for diode laser systems is contemplated whereby the circuitry is both modular and minimally complex with respect to the number of components and connections.

Abstract: An adder adds a phase ?plus, which is n times a size of 60 degrees, to a phase output from a phase switching unit and outputs the phase as a voltage command phase ?. A voltage generation unit generates voltage command value based on the voltage command phase output by the adder and outputs the command value. A drive-signal generation unit, based on an output from the voltage generation unit generates drive signals corresponding to respective switching elements of an inverter, and outputs respective generated drive signals to the corresponding switching elements of the inverter, and generates a high-frequency AC voltage in the inverter.

Abstract: A method and apparatus for powering up and powering down a laser diode and its driver are disclosed. The disclosed method and apparatus enable the use of deep sub-micron CMOS technology to build a laser diode driver (LDD), while ensuring the low voltage limits prescribed by such technology are not exceeded. Building an LDD with deep sub-micron CMOS technology pushes circuit integration further ahead, bringing cost of LDDs and required board circuits down.

Abstract: This invention relates to methods and apparatus of a combination of multi-laser wave mixing technology with diagnostic flow system with embodiments describing capillary electrophoresis. The unique combination of these technologies along with minute detection levels not yet been seen in the field.

Abstract: A transmitter module that includes a laser diode (LD) and a driver, each mounted on a sub-mount, is disclosed. The driver directly drives the LD by supplying a modulation signal, a bias signal, and a reference. Two signals are provided to a first pad of the LD, while, the reference is provided to the second pad of the LD. The second pad in the center thereof is formed relatively closer to the second facet of the LD opposite to the first facet through which the laser light is emitted.

Abstract: A driving apparatus and method for a dimmable LED is provided. The apparatus includes a dimmer switch which controls connection or disconnection of an LED series. The apparatus further includes: a boost circuit electrically coupled to the LED series; a comparator electrically coupled to the boost circuit, the comparator receiving a triangle wave signal to generate a PWM signal, the PWM signal controlling the boost circuit; and a RC circuit electrically coupled to the comparator, the RC circuit utilized to output a charging curve signal to the comparator when the dimmer switch disconnects, thereby improving noise and electromagnetic interference of the boost circuit.

Abstract: One embodiment of the present invention sets forth a mechanism for transmitting and receiving differential signals. A transmitter combines a direct current (DC) to DC converter including a capacitor with a 2:1 multiplexer to drive a pair of differential signaling lines. The transmitter drives a pair of voltages that are symmetric about the ground power supply level. Signaling currents are returned to the ground plane to minimize the generation of noise that is a source of crosstalk between different differential signaling pairs. Noise introduced through the power supply is correlated with the switching rate of the data and may be reduced using an equalizer circuit.

Abstract: A burst-mode laser control circuit and related methods thereof are disclosed. Using an APC loop with an additional burst-mode control circuit, and a switch in series with a diode and in parallel with the laser, a continuous-mode laser driver is enabled to operate in burst-mode by turning the switch on or off via external logic. Burst-mode control manages the switch, and a bandwidth-select circuit using a high or low logic level input, wherein the laser is disabled and the bandwidth-select circuit enters a fast-track mode when the external logic signal has a first level. The laser provides regular optical signals, and the bandwidth-select circuit enters a slow-track mode, thereby enabling the APC loop to operate normally, when the external logic signal has a second level. In addition to a low cost and simple implementation, the control circuit and method provide lasers with a fast response capability using one or more externally-controlled switch circuits to meet demands of PON systems for burst-mode ONUs.

Abstract: An optical module capable of monitoring an inner temperature thereof by a simple arrangement is disclosed. The optical module installs an avalanche photodiode (APD). The APD generates the first photocurrent under a bias where the APD shows the multiplication factor thereof M equal to the unity, and the second photocurrent under another bias where the multiplication factor becomes greater than the unity. The operating temperature of the laser diode (LD) may be estimated from a ratio of the first photocurrent to the second photocurrent.

Abstract: A lighting device includes a AC/DC or DC/DC power converter, a controller/processor electrically connected to the AC/DC or DC/DC power converter, a light emitting diode (LED) current control circuit communicably coupled to the controller/processor and electrically connected to the AC/DC or DC/DC power converter, and one or more LEDs electrically connected to the LED current control circuit.

Abstract: A supercontinuum source capable of emitting waves between the infrared range and the ultraviolet range, includes a pulsed laser source (12) capable of generating a laser beam and a non-linear microstructured optical fiber (14) capable of receiving the laser beam, in such a way that the supercontinuum source is capable of generating a beam (F?) over a pulse duration (T?), characterized in that the supercontinuum source includes elements for varying the pulse duration.

Abstract: Technologies are generally described for implementing non-linear VCSEL equalization. In some examples, a rising edge tap parameter, a falling edge tap parameter, an equalization delay and a bias current may be used to equalize a data signal to be output from a VCSEL. A VCSEL model may be used to derive a VCSEL response to one or more isolated data pulses. The derived response may then be used to determine the rising and falling edge tap parameters and an equalization delay, based on a bias current value for the VCSEL and a data rate associated with the data signal. The data signal may then be adjusted based on the equalization delay and the rising and falling edge tap parameter and sent to the VCSEL for output. At the same time, the VCSEL may be biased with a bias current having the bias current value.

Abstract: Symmetrical, direct coupled laser drivers for high frequency applications. The laser drivers are in integrated circuit form and use a minimum of relatively small (low valued) external components for driving a laser diode coupled to the laser driver through transmission lines. An optional amplifier may be used to fix the voltage at an internal node at data frequency spectrum to improve circuit performance. Feedback to a bias input may also be used to fix the voltage at the internal node. Programmability and a burst mode capability may be included.

Abstract: An optical transmitter is disclosed. In accordance with some embodiments of the present disclosure, an optical transmitter may comprise a vertical-cavity surface-emitting laser (VCSEL) and a VCSEL driver. The VCSEL driver may comprise an input stage configured to receive a voltage signal and a low-impedance output stage comprising an input coupled to the input stage and a low-impedance output coupled to the VCSEL and configured to provide a modulated output current to the VCSEL.

Abstract: In exemplary embodiments, an ultra short pulse system comprises a laser platform which includes an optical source configured to generate an optical pulse, an optical amplifier configured to amplify the optical pulse, and a compressor configured to temporally compress the amplified optical pulse. The ultra short pulse system further comprises monitor circuitry configured to monitor one or more performance aspects of the laser platform. Additionally, the ultra short pulse system may comprise logic configured to control the one or more performance aspects of the laser platform in response to at least the monitored one or more performance aspects.

Abstract: A semiconductor laser drive apparatus includes: a current setting circuit that stores a first set value for a light-emission current obtained by subtracting a first bias current used when the semiconductor laser element emits light, from a drive current used when the semiconductor laser element emits light, a second set value for the first bias current, and a third set value for a second bias current used when the semiconductor laser element does not emit light; a first current generator circuit that generates a first input current from the first set value; a second current generator circuit that generates a second input current from the second set value and a third input current from the third set value; and a switching circuit that supplies a sum of the first and second input currents to a drive circuit when a light-emission control signal is on, and the third input current to the drive circuit when the light-emission control signal is off.

Abstract: A gas laser oscillator including a discharge tube provided in a gas channel through which a laser gas circulates; an output command part outputting a power output command; a power supply part applying to the discharge tube a discharge tube voltage corresponding to a power output command value; a voltage detector detecting the discharge tube voltage; and a discharge start judging part judging if a discharge has been started in the discharge tube based on a ratio of change of the discharge tube voltage. The output command part increases the power output command value in steps by an increment obtained by dividing a power output command value corresponding to a discharge start voltage serving as a predetermined reference by a number of steps of 2 or more, at a step time interval determined by using as a reference the time required until the power supply part responds to the power output command.

Abstract: A drive circuit includes a bias current supply circuit for supplying a bias current to a light-emitting device for transmitting an optical signal, the light-emitting device included in a light-emitting circuit; and a modulation current supply circuit for supplying a modulation current of a magnitude according to a logical value of data to be transmitted, to the light-emitting device. The modulation current supply circuit includes a differential drive circuit for switching whether to supply a current to the light-emitting device, according to the logical value of the data; and a termination resistor connected between differential outputs of the differential drive circuit. The differential drive circuit and the light-emitting circuit are DC-coupled to each other, and power supply of the current supplied to the light-emitting device by the differential drive circuit is supplied from the light-emitting circuit.

Abstract: An image forming apparatus controls a semiconductor laser such that first and second light beams among multiple light beams are successively incident on a BD sensor and measures the time interval between BD signals that correspond to the first and second light beams and are output from the BD sensor. Two light emitting elements that output two light beams for which the ratio between the light powers of two light beams detected by the detection unit falls within a predetermined range are set as light emitting elements that are to emit the first and second light beams when the time interval is to be measured. This suppresses measurement errors when measuring the interval between light beams emitted from two light emitting elements and improves correction accuracy for the image writing start positions of the light emitting elements.

Abstract: Methods and devices for laser driver calibration are disclosed. The methods and devices disclose determining first and second bit error rates for use in calibrating the laser driver. The methods and devices also disclose that if the first bit error rate associated with a first initial value is above a predetermined bit error rate, increasing the first initial value until the first bit error rate is not above the predetermined bit error rate, and if the second bit error rate associated with a second initial value is above a predetermined bit error rate, decreasing the second initial value until the second bit error rate is not above the predetermined bit error rate. In addition, the methods and devices disclose setting a calibrated parameter for the laser driver based, at least in part, on the increased first initial value and the decreased second initial value.

Abstract: A method and apparatus for optimizing a light emitting diode (LED) operation range is provided. The method comprises the steps of: turning on at least one LED; and then measuring an anode voltage of the at least one LED; then measuring a cathode voltage of the at least one LED. Once the measurements are completed, a forward voltage of the at least one LED is calculated. After the calculation, the at least one LED is turned off and a power multiplexer switch threshold is set for that LED based on the measured anode and cathode voltages.

Abstract: An optical module includes: an optical device driven by a driving voltage; an arithmetic processing chip including an arithmetic processing circuit that operates according to predetermined firmware and generates an electrical control signal indicating a magnitude of the driving voltage; a voltage generating unit provided outside the arithmetic processing chip, and including an input terminal that receives the control signal from the arithmetic processing chip and an output terminal that provides the driving voltage of a magnitude corresponding to the control signal to the optical device; and a voltage holding unit that holds an output voltage from the output terminal of the voltage generating unit at a constant voltage regardless of an operation state of the arithmetic processing circuit, when the firmware is updated.

Abstract: A disk drive is disclosed comprising a disk and a head comprising a laser configured to heat the disk while writing to the disk. At least one transmission line couples a laser driver to the laser. Data is written to the disk by pulsing the laser driver, wherein the transmission line comprises an impedance that results in a target pulse shape of optical power output by the laser.

Abstract: Various embodiments of the present invention relate to a laser driver, and more particularly, to systems, devices and methods of applying low current pulses to a laser modulation current to reduce the speckling noise on the projected images.

Abstract: The existing diodes in an LED or laser diode package are used to measure the junction temperature of the LED or laser diode. The light or laser emissions of a diode are switched off by removing the operational drive current applied to the diode package. A reference current, which can be lower the operational drive current, is applied to the diode package. The resulting forward voltage of the diode is measured using a voltage measurement circuit. Using the inherent current-voltage-temperature relationship of the diode, the actual junction temperature of the diode can be determined. The resulting forward voltage can be used in a feedback loop to provide temperature regulation of the diode package, with or without determining the actual junction temperature. The measured forward voltage of a photodiode or the emissions diode in a diode package can be used to determine the junction temperature of the emissions diode.

Abstract: The invention relates to solid state light source, a use of a driver circuit for driving a light emitting element (150) of a solid state light source, a method for driving a light emitting element (150) of a solid state light source and a corresponding computer program. The invention provides that for a large amount of an AC period the light emitting element (150) is directly supplied with the AC input directly forwarded by the driver circuit, wherein nevertheless it is prevented that power exceeding a desired level reaches the light emitting element (150). The invention is aimed at a realization with simplified components and/or reduced costs in comparison to known techniques.

Abstract: A temperature-compensated laser driving circuit for driving a laser component is provided. The temperature-compensated laser driving circuit includes: a temperature compensation circuit, configured to generate a second current based on a first current and a temperature-independent current; and a modulation current generating circuit, configured to generate a modulation current based on the second current, and calibrate optical power output of the laser component based on the modulation current. The first current is proportional to the absolute temperature. The second current and the first current have a slope relative to the absolute temperature respectively, and the slope of the second current relative to the absolute temperature is larger than of the slope of the first current relative to the absolute temperature.

Abstract: The laser mount arrangement can have a laser bar and a driver positioned adjacent to one another and secured against a connection face of a heat sink base. The heat sink base is connected to and forms a first electrical connection between the laser bar and the driver. A second electrical connection is also provided between the laser bar and the driver opposite the heat sink base, which can be in the form of a flexible metal sheet with a narrow upward fold. This arrangement can provide a low inductance path for the current.

Abstract: A microlaser system includes an optical source, a microlaser, an actuator switch, and a photovoltaic power source. The microlaser, which includes a control element, is optically pumped by at least a portion of light emitted by the optical source. The actuator switch is configured to be activated by a triggering event. Furthermore, the photovoltaic power source is coupled in a series connection with the actuator switch and the control element, the series connection configured to connect the photovoltaic power source to the control element of the microlaser when the actuator switch is activated by the triggering event.

Abstract: A laser driver circuit having a differential circuit and an output circuit includes a control circuit receiving a regulated supply voltage that also supplies the differential circuit as an input signal. The control circuit generates a feedback voltage across a first resistor to cause a first current to flow in the first resistor having a current value equal or proportional to the modulation current value. The laser driver circuit includes an operational amplifier receiving the feedback voltage and a reference voltage indicative of a desired modulation current value and to generate the regulated supply voltage. The control circuit and the operational amplifier form a feedback control loop to adjust the regulated supply voltage to regulate the feedback voltage to be equal to the reference voltage, thereby regulating the modulation current value to the desired modulation current value.

Abstract: The present invention discloses a driving circuit including a rectifying circuit and a first current-controlling circuit. Input terminals of the rectifying circuit are connected to output terminals of an AC power source. The first current-controlling circuit and a plurality of light-emitting elements be driven are connected in series, and then are connected between two output terminals of the rectifying circuit. The driving circuit further includes a plurality of switches and a switch-controlling circuit; the switches are connected in parallel with two terminals of one or some light-emitting elements connected in series to form many light-emitting element subunits. Control-signal output terminals of the switch-controlling circuit are connected to control terminals of the switches respectively, to control the switches in an ON-OFF state according to an instantaneous value of a DC voltage outputted from the rectifying circuit, for controlling an amount of light-emitting elements which should be lighten.

Abstract: Methods, systems, and computer-readable mediah are provided for operating a vertical-cavity surface-emitting laser. Operating a vertical-cavity surface-emitting laser can include sending a signal to a driver to decrease an optical power of a vertical cavity surface emitting laser transmitter, and sending a signal to the driver associated with increasing the optical power by a particular amount in response to determining that the optical power is insufficient for reception by a receiver.

Abstract: Provided are assemblies and processes for activating light emitting devices. A first current sink is in electrical communication with a common source through a current node and configured to draw a first current through the current node in response to a respective control signal. A second current sink is also provided in electrical communication with the current node and in parallel with the first current sink, also configured to draw a second current through the current node in response to a respective control signal. An aggregate current is drawn through the array, determined as a combination of the first and second currents. A commanded current from the first current sink can be shunted around the second array and the second current sink, providing a capability to series both the first and second laser diode light-emitting arrays, while simultaneously drawing different current amplitudes through each array from a common potential source.

Abstract: A transmitter module that includes a laser diode (LD) and a driver, each mounted on a sub-mount, is disclosed. The driver directly drives the LD by supplying a modulation signal, a bias signal, and a reference. Two signals are provided to a first pad of the LD, while, the reference is provided to the second pad of the LD. The second pad in the center thereof is formed relatively closer to the second facet of the LD opposite to the first facet through which the laser light is emitted.

Abstract: A laser driver subsystem includes a pump diode driver, operable to generate light pulses to energize a laser, and a lithium polymer battery. The pump diode driver includes a pump diode and a switched-mode power conversion circuit at an input connected to an output of the battery and at an output connected to an anode of the pump diode. The switched-mode power conversion circuit is configured to convert an electrical voltage from a first level at the output of the battery to a second lower voltage level at the pump diode anode so as to provide the pump diode with an electrical current that enables the pump diode to generate the light pulses to operate the laser while only a fraction of that current needs to be supplied by the battery.

Abstract: There provided is a semiconductor laser control device which including plural light sources that are configured with eight or more semiconductor laser elements, a one detecting section that detects a light power of the light sources, a light power control unit that compares a signal according to a light power detected by the detecting section with a control signal corresponding to a predetermined light power to control a current supplied to the light sources, and a voltage clamp circuit that functions as an overvoltage preventing means for the detecting section when turning on each of the light sources to perform light power control.

Abstract: Methods and circuits for providing a minimum driving voltage to a current-driven load (such as a laser diode) are disclosed. The circuit and methods may be useful for efficiently providing a bias and/or driving current to the current-driven load with minimal energy loss. The circuit generally comprises (1) a driver or voltage source configured to provide the bias and/or driving current to the current-driven load, (2) a sense circuit configured to (i) sense the bias and/or driving current and (ii) convert the bias and/or driving current to a first voltage, and (3) a comparator configured to (i) receive the first voltage and first and second reference voltages and (ii) provide a feedback/error signal to the driver or voltage source, the feedback/error signal configured to maintain or adjust the bias and/or driving current at or towards a target value.

Abstract: In a VCSEL driver for automatic bias control and automatic modulation control, the VCSEL driver includes: a feedback module configured to receive an output of a VCSEL to provide a bias signal through a feedback loop; an automatic bias control block configured to adjust a bias current by switching on or off a plurality of power sources, which are connected in parallel with each other; an automatic modulation control block configured to connect in parallel a plurality of bias transistors that are connected to each of the plurality of power sources, and to adjust modulation current by switching each of the plurality of bias transistors on or off; and a main driver configured to provide the VCSEL with a drive current including the bias current and the modulation current, which are adjusted by control of each of the control blocks.

Abstract: A laser light source module includes a laser source, a connecting unit, a controlled switch unit, and a verification unit. When a verification signal is received, the verification unit judges whether the verification signal complies with a verifying condition. If the verification signal complies with the verifying condition, the controlled switch unit is in the on state, so that a first output voltage is transmitted to the laser source through the controlled switch unit to drive illumination of the laser source. Whereas, if the verification signal does not comply with the verifying condition, the controlled switch unit is in the off state, so that the first output voltage fails to be transmitted to the laser source through the controlled switch unit and the laser source is turned off.

Abstract: A driving method of a laser diode includes setting a bias current, a modulation current, a first target corresponding to a predetermined average power, and a second target corresponding to a predetermined average modulation power; executing a first adjusting current step group; generating a temporary modulation current according to the modulation current; executing a second adjusting current step group; and executing the first adjusting current step group again.

Abstract: A driving method of a laser diode includes setting a bias current, a modulation current, a first target corresponding to a predetermined average power, and a second target corresponding to a predetermined average modulation power; executing a first adjusting current step group; generating a temporary modulation current according to the modulation current; executing a second adjusting current step group; and executing the first adjusting current step group again.

Abstract: A driving device includes: a driving circuit configured to provide a drive current; a first detecting circuit; a second detecting circuit configured to detect a first reference current or a physical quantity corresponding thereto, as well as a second reference current or a physical quantity corresponding thereto; a first generating circuit configured to generate an additive voltage as a control voltage at a light-emission time of a light-emitting element, and further to generate a second voltage as a control voltage at a non-light-emission time of the light-emitting element; and a second generating circuit configured to generate a third reference current. The second detecting circuit has a first adder circuit that generates the first reference current by adding the second reference current and the third reference current with each other.

Abstract: A lasing wavelength of a laser diode is determined by applying a forward current to the p-n junction of the laser diode and measuring a voltage across the p-n junction. The lasing wavelength can be determined by performing a simple wavelength calibration of the laser diode. This allows one to stabilize the lasing wavelength, and also to use the laser diode as a reference wavelength source.

Abstract: Symmetrical, direct coupled laser drivers for high frequency applications. The laser drivers are in integrated circuit form and use a minimum of relatively small (low valued) external components for driving a laser diode coupled to the laser driver through transmission lines. An optional amplifier may be used to fix the voltage at an internal node at data frequency spectrum to improve circuit performance. Feedback to a bias input may also be used to fix the voltage at the internal node. Programmability and a burst mode capability may be included.