Abstract: In an optical supply arrangement, a laser source (10) provides transmitted laser light down an optical supply line (12, 14). A first coupler (16), remote from the laser source (10) along the optical supply line (14), taps off a small proportion of the transmitted laser light to be returned along the optical supply line (14) to a photo detector (26) driving a monitor (28) and a controller (30). If the monitor (28) detects that the photo detector (26) is experiencing a loss of return laser light, possibly due to a break in the optical supply line (14), the monitor (28) causes the controller (30) to extinguish the laser source (10) in less time than escaping laser light can cause damage to property, person or eyesight. A first embodiment has the transmitted light on a transmission fiber optic (12) and the return laser light on a separate return fiber optic (24). A second embodiment has the return laser light being sent back down the transmission fiber optic (12).

Abstract: An apparatus and method for a laser light projector, including a laser beam generated by a laser light source; a scanner associated with the laser light source and having one or more moving mirrors capable of scanning the laser beam along X-Y coordinates; a power meter positioned for quantifying the laser beam's power in real time; a fault detector operably connected in the laser light projector to detect a fault condition and automatically generate a fault signal in response thereto; a modulator responsive to the fault signal for reducing power in the laser beam; and a fault shutter operably associated with the laser light source and responsive to the fault signal so as to shut off the laser beam.

Abstract: A laser unit having a preparatory function for activating the unit and an activation method for the unit, capable of stabilizing the temperature of each component of the laser unit in the preparation stage when the laser unit is activated in a low-temperature or high-temperature environment, and then effectively judging completion of the preparation. During a period of time Ta from T1 to T2, a first trial of laser oscillation is performed. After a period of time Tb in which the laser is not oscillated, a second trial of laser oscillation from T3 to T4. Such an operation is repeated until a predetermined criterion is satisfied. Laser output values P2, P4, P6, . . . , at the last moment in each trial of laser oscillation are recorded. Then, each difference between the laser outputs at the last moments of two neighboring or continuous trials, is calculated. When the difference is lower than a predetermined criterion value, the preparation of the laser unit is judged to be completed.

Abstract: A light source device includes: a light emitting element; a pulse drive section adapted to supply the light emitting element with a pulse current in order for controlling an average emission light intensity from the light emitting element; and a light emitting element shunt section disposed in parallel to the light emitting element and adapted to shunt the light emitting element.

Abstract: Laser power control arrangements interrupt power to a laser used in electro-optical readers upon detection of an over-power condition not conforming to preestablished regulatory standards. In one embodiment, during an operational mode, a difference between laser drive currents at two operating points is compared to a difference between laser drive currents at the same two operating points during a calibration mode. The over-power condition is recognized when the difference during the operational mode exceeds the difference during the calibration mode by a predetermined amount. In another embodiment, the laser is only energized to emit the beam at a reduced power level well below regulatory standards for staring at even if a motor drive failed.

Abstract: Red, blue and green lasers respectively emit a plurality of red, blue and green laser beams having respective output powers. The beams are optically focused and collinearly arranged to form a composite beam which is swept by a pair of scan mirrors in a pattern of scan lines on a projection surface, each scan line having a number of pixels. A controller causes selected pixels to be illuminated, and rendered visible, by the composite beam to produce an image. A safety circuit detects a malfunction of at least one of the lasers and the scan mirrors, and deenergizes the at least one of the lasers and the scan mirrors upon detection of the malfunction.

Abstract: A pulse oscillating type solid laser unit that has a laser unit body whose exciting source is a laser diode that emits light in a principal energy absorbing spectrum of a solid laser activated media, and characterized by that prior to radiating laser light outside the laser unit body as a calibrating operation of a pulse laser output value, specified several varieties of rectangle pulse current values are conducted to a laser diode inside the pulse oscillating type solid laser unit so as to pulse-oscillate the laser unit body, a mean laser output value in each rectangle pulse current value is measured by the use of a laser output measuring instrument arranged inside the laser unit body so as to obtain a mean laser output value data, and in case that the laser output light is radiated outside the laser unit body, a pulse current value linear-predicted based on an obtained mean output value data is conducted to the laser diode so as to obtain a desired pulse laser output value.

Abstract: A gas discharge laser system bandwidth control mechanism and method of operation for controlling bandwidth in a laser output light pulse generated in the gas discharge laser system is disclosed which may comprise a bandwidth controller which may comprise an active bandwidth adjustment mechanism; a controller actively controlling the active bandwidth adjustment mechanism utilizing an algorithm implementing bandwidth thermal transient correction based upon a model of the impact of laser system operation on the wavefront of the laser light pulse being generated and line narrowed in the laser system as it is incident on the bandwidth adjustment mechanism. The controller algorithm may comprises a function of the power deposition history in at least a portion of an optical train of the gas discharge laser system, e.g., a linear function, e.g., a combination of a plurality of decay functions each comprising a respective decay time constant and a respective coefficient.

Abstract: In an optical wavelength control circuit, an activation control circuit outputs an optical output setting signal to a laser unit to set its optical output, and simultaneously outputs a temperature setting signal and a wavelength setting signal. A temperature error detection circuit outputs a temperature error signal. A wavelength error detection circuit outputs a wavelength error signal. A control switching circuit receives the temperature error signal and the wavelength error signal, selectively outputs the temperature error signal as a control error signal in the activation operation, and selectively outputs the wavelength error signal as the control error signal in a steady-state operation after the activation operation. A steady-state error removing circuit removes a steady-state error contained in the control error signal and outputs a temperature controller control signal.

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: Laser power control arrangements interrupt power to a laser used in electro-optical readers upon detection of an over-power condition not conforming to preestablished regulatory standards. In one embodiment, during an operational mode, a difference between laser drive currents at two operating points is compared to a difference between laser drive currents at the same two operating points during a calibration mode. The over-power condition is recognized when the difference during the operational mode exceeds the difference during the calibration mode by a predetermined amount. In another embodiment, the laser is only energized to emit the beam at a reduced power level well below regulatory standards for staring at even if a motor drive failed.

Abstract: The invention discloses an optical transmission module with digital adjustment and method thereof. The module includes a laser (21), a laser driver (22), an automatic power adjustment circuit (23), an automatic temperature adjustment circuit (24), a digital adjustment circuit (25) and a memory (26). The digital adjustment circuit, consisted of a digital-to-analog converter or a digital adjustment potentiometer, receives a digital adjustment signal and outputs, respectively, a extinction ratio adjustment signal and a cross point adjustment signal to the laser driver, an optical power adjustment signal to the automatic power adjustment circuit and an optical wavelength adjustment signal to the automatic temperature adjustment circuit. The memory stores data, using for on-line adjustment of the optical transmission module, at least including parameters of said optical transmission module and said laser emitting optical power parameters, to be reported upward.

Abstract: An integrated circuit for providing burn-in current to a laser diode. The integrated circuit includes a laser driver having an output for connection to the laser diode. Burn-in circuitry is formed on the integrated circuit and generates a burn-in current. A switch is formed on the integrated circuit and couples the burn-in current to the laser diode in response to an enable signal.

Abstract: The present invention provides an optical transmitter that prevent the overshoot and undershoot appeared in the emission wavelength caused by the fluctuation of the temperature of the laser diode installed therein. The optical transmitter includes a TEC driver, and a master controller. The TEC driver, by comparing the monitored temperature with the target temperature, outputs the error signal to the master controller, which enables the LD-Driver only when the error signal continuously stays within a convergent range by a preset period.

Abstract: A laser power control circuit that is constituted by CMOS transistors reduces variations in a laser power that is emitted from a semiconductor laser, which are caused by a mismatch of the transistors. An offset amount of a differential amplifier is digitally calculated using an A/D converter that is located on the same chip, and a voltage value of a variable voltage source is controlled for applying a voltage in a direction opposite to the offset voltage of the differential amplifier to correct the offset voltage of the laser power control circuit, thereby reducing the variations in the laser power emitted from the semiconductor laser.

Abstract: An apparatus and method to safely control the power output of a laser source. A power monitor is optically coupled to monitor a power output of laser source generating an optical signal. The power monitor is coupled to generate power feedback data indicative of the power output. A processor is coupled to control the power output of the laser source in real-time in response to the power feedback data from the power monitor.

Abstract: Circuitry for reliably regulating the current driving a laser diode or other current-driven load is described. In particular, a dual-current driver circuit is described that uses both a current source circuit and a current sink circuit. The current source circuit and the current sink circuit may each independently control the laser diode drive current within a desired operating tolerance. The current driving the laser diode will be maintained within tolerance despite the failure of either the current source circuit or the current sink circuit. This is because the current source circuit and the current sink circuit are combined with the laser diode in series, such that the current driving the laser diode will be controlled at the lower of the two currents driven by the current source circuit and the current sink circuit.

Abstract: A laser driver IC has an RS flip-flop for latching a signal that indicates an event of fault detection, to output it as an internal fault signal, and a fault signal processing section for generating a disable signal for inactivating the driving function of the laser driver IC in response to output of the RS flip-flop. One of outputs of the fault signal processing section is connected to a fault signal output terminal linked to outside the laser driver IC.

Abstract: Systems, methods and apparatuses for guaranteeing a shut-down time for a laser in a laser surgical unit are presented. More particularly, embodiments of such methods, systems and apparatuses may provide shut-down logic which comprises a timer which may be triggered by a signal received from an event. At the expiration of the timer a signal may be output which is configured to disable the output of the laser. Specifically, in one embodiment, software may be used to configure a shut-down time and a set of events to be utilized to start the timer. Upon firing of the laser the timer will be enabled. During the operation of the laser then, if one of the set of events occurs the timer will be triggered such that at the end of the shut-down time the output of the laser will be disabled.

Abstract: A current output of a drive signal, modulated between two current settings, is applied to a laser diode, e.g. VCSEL. The settings are selected such that laser diode's power output meets the average power and peak power limits of the eye safety standards. The drive signal having a duty cycle toggling between the two settings. The duty cycle is selected such that the average and peak power limits are met for the given upper current setting. The drive circuit may include an analog modulator or digital analog converter (DAC) for maintaining the lower and upper current settings. When the drive circuit is implemented as an integrated circuit, the DAC may be incorporated into the IC. The sensitivity of the DAC is selected to maintain the desired lower and upper current settings.

Abstract: The present invention provides an optical transmitter that enables to distinguish failure modes of the auto-power control (APC) of the laser diode (LD). The transmitter provides the APC circuit comprised of the driver for supplying the driving current, the LD, the PD for monitoring a portion of the output light from the LD, and the control unit for setting the driving current. The control unit monitors, at regular intervals, the bias current to the LD and the time differential of the bias current. The control unit only stops the APC circuit when both the bias current and the time differential of the bias current exceed respective references.

Abstract: The present invention provides a method and apparatus, such as an integrated circuit, to control the optical midpoint power level and the extinction ratio of a semiconductor laser and maintain the optical midpoint power level and the extinction ratio substantially constant at corresponding predetermined levels. Apparatus embodiments include a semiconductor laser, a modulator, a photodetector, an optical midpoint controller, and an extinction ratio controller. The semiconductor laser is capable of transmitting an optical signal in response to a modulation current. The modulator is capable of providing the modulation current to the semiconductor laser, with the modulation current corresponding to an input data signal. The photodetector, which is optically coupled to the semiconductor laser, is capable of converting the optical signal into a photodetector current.

Abstract: An optical element includes: a substrate; a surface-emitting type semiconductor laser that is provided on the substrate and emits laser light in a direction orthogonal to a surface of the substrate; a rectification element that is provided on the substrate and connected in parallel with the surface-emitting type semiconductor laser, the rectification element having a rectification action with respect to a reverse bias voltage applied to the surface-emitting type semiconductor laser; a first insulation layer that covers a side surface and a portion of an upper surface of a first columnar section including at least a portion of the surface-emitting type semiconductor laser; and a second insulation layer that covers a side surface and an upper surface of a second columnar section along an entire circumference thereof, the second columnar section including at least a portion of the rectification element.

Abstract: An apparatus and method for a laser light projector, including a laser beam generated by a laser light source; a scanner associated with the laser light source and having one or more moving mirrors capable of scanning the laser beam along X-Y coordinates; a power meter positioned for quantifying the laser beam's power in real time; a fault detector operably connected in the laser light projector to detect a fault condition and automatically generate a fault signal in response thereto; a modulator responsive to the fault signal for reducing power in the laser beam; and a fault shutter operably associated with the laser light source and responsive to the fault signal so as to shut off the laser beam.

Abstract: Laser protection arrangement with a safety cutoff comprising a passive laser protection wall which stores the radiation energy of impinging radiation of a laser of a laser material processing installation, a laser protection foil which causes a detectable change when struck by laser radiation and which is arranged in front in direction of the laser radiation, and at least one sensor which is connected to the laser by a threshold switch in order to switch off the laser when the received detector signal exceeds or falls below a threshold value.

Abstract: A voltage dividing apparatus for preventing sudden increases in power to a laser diode includes a laser diode module, a laser-driving unit and a Zener diode. The laser diode module includes a laser diode for receiving a driving current to emit light, and a photo diode for receiving the light emitted from the laser diode and transferring the light signal into a voltage signal. The voltage signal is fed back to the laser diode module for automatically balancing the power of the laser diode. The laser-driving unit is used for driving the laser diode to output power. When the circuit shorts, two voltage-dividing resistors and the Zener diode disable the laser-driving unit to protect the laser diode. It blocks the laser diode's outputting power to prevent the outputting power from suddenly increasing and prevent the laser with strong power from hurting a user's eyes.

Abstract: A laser scanning device includes a semiconductor laser that emits a laser beam, a laser power detector that detects laser beam power of the semiconductor laser, a reference voltage generator that generates reference voltage for controlling the laser beam power of the semiconductor laser in accordance with a laser power control signal provided from an external device, and a laser driver that compares the reference voltage generated by the reference voltage generator and the laser beam power detected by the laser power detector to control a driving current supplied to the semiconductor laser for emitting the laser beam. The laser scanning device further includes an abnormal condition detector that detects the laser power control signal received by the reference voltage generator.

Abstract: A circuit for disabling an energy-generating component. The circuit comprises an input operable to receive a disable signal and a disable circuit operable to disable the component in response to the disable signal for a predetermined duration of time sufficient to maintain an average power generated by the component at or below a predetermined level. The disable circuit further comprises a signal-detection circuit operable to detect the presence of disable signals having a respective rising edge and falling edge, a mask-signal generating circuit coupled to the signal detection circuit and operable to generate a mask signal when one of the edges of a first disable signal is detected; and a latching circuit coupled to the mask-signal generating circuit and operable to generate a mask disable signal if the mask signal is being generated and the other edge of a subsequent disable signal is detected.

Abstract: An eye safety detection circuit for use in a laser transmitter. The eye safety detection circuit shuts the laser down if the laser is emitting excessive optical energy to the point of being unsafe to a user. The eye safety detection circuit includes a laser current detection circuit that is configured to detect when there is a potential that the laser is emitting light at levels that exceed a predetermined threshold. If the laser were to immediately turn off under this condition, the laser may be turned off prematurely. Instead, the eye safety detection circuit includes a timer circuit that causes the laser to cease operation only after one or more such conditions have been met for a predetermined period of time.

Abstract: A current output of a drive signal, modulated between two current settings, is applied to a laser diode, e.g. VCSEL. The settings are selected such that laser diode's power output meets the average power and peak power limits of the eye safety standards. The drive signal having a duty cycle toggling between the two settings. The duty cycle is selected such that the average and peak power limits are met for the given upper current setting. The drive circuit may include an analog modulator or digital analog converter (DAC) for maintaining the lower and upper current settings. When the drive circuit is implemented as an integrated circuit, the DAC may be incorporated into the IC. The sensitivity of the DAC is selected to maintain the desired lower and upper current settings.

Abstract: A system and method is disclosed for improving the safety of directionally sensitive medical and industrial applications, such as laser applications, and cutting or surfacing tools. A system of electromagnetic radiation safety beam emitters and detectors is used to prevent a user from directing or positioning an application device, such as an electromagnetic beam source or high-power water jet, to areas outside a predefined application area and also to prevent operation of an application beam should persons or objects intersect a security boundary. In a first preferred embodiment, one or more safety beam emitters are placed in or near a treatment area, and a “safety beam” produced by the emitter is preferably directed toward the preferred position of the source of the application beam. In a second preferred embodiment, the safety beam emitter(s) is directed toward the application area of the source, and the detectors detect radiation reflected from the application area.

Abstract: There is provided a laser driving circuit having a small circuit scale which is capable of low voltage operation and in which unnecessary writing in an optical disc, or the like, is entirely prevented. To this end, the laser driving circuit includes a source-grounded amplifier to which the supply voltage of the first power supply is supplied as well as to a laser driving circuit block and to which the voltage of the second power supply of a control circuit block is input. A bias input terminal of a differential amplifier is pulled up according to an output of the source-grounded amplifier till the voltage of the second power supply rises, whereby an output of the laser driving circuit block is suppressed. With such a structure, unnecessary emission of a semiconductor laser, breakage of the semiconductor laser, etc., are prevented.

Abstract: A laser beam irradiation device is equipped with a very strict safety arrangement, thereby assuring that a user can use it safely. A hand-held applicator has a face formed on its top, and a push button switch on its side. The face has a spherical lens press-fitted in its center hole, and the face has a hollow cylinder integrally connected to its circumference, encircling the spherical lens. The hand-held applicator is applied to one's skin by the hollow cylinder at its edge. The hollow cylinder has a cylindrical electrode embedded in and somewhat projecting forward. A heat sink is placed behind the spherical lens, and a semiconductor laser diode is press-fitted in the through hole, which is made in the center of the heat sink. A cooling fan is placed behind the heat sink.

Abstract: A semiconductor laser device in a semiconductor-laser excited solid-state laser apparatus is provided with a plurality of semiconductor laser diodes connected in series to one another. Each of a plurality of bypass diodes is connected in parallel to each semiconductor laser diode or each group of at least two semiconductor laser diodes in the plurality of semiconductor laser diodes and has a higher rising voltage than a rising voltage of the parallel-connected semiconductor laser diodes. The polarity of one end of each of the semiconductors laser diode is the same as the polarity of that end of the associated bypass diode which is connected to the one end of that semiconductor laser diode and the polarity of the other end of the semiconductor laser diode is the same as the polarity of that end of the associated bypass diode which is connected to the other end of that semiconductor laser diode.

Abstract: A light emitter includes an emitting stack, a first electrode, a second electrode and a voltage dependent resistor layer. The emitter stack has a first surface area and a second surface area. The first electrode is formed on the first surface area of the emitting stack. The second electrode is formed on the second surface area of the emitting stack. The voltage dependent resistor layer is connected to the first and second electrodes, and is formed during the formation of the light emitter thus improving the yield of the light emitter.

Abstract: A method and circuit for measuring the optical modulation amplitude in the operating region of a laser diode is described. The method utilises two measurements of OMA, each measurement being related to the slope in a specific portion of the operating region of the power/current characteristic curve of the laser diode. By combining the two measurement values, the invention provides a 1 measurement for OMA in the operating region of the laser diode that allows for the presence of a non-linear response in the region.

Abstract: In an arrangement of a plurality of high-power diode lasers, each of which contains a semiconductor laser between a heatsink and a cover element, the semiconductor lasers being connected in series by their electrical contacts, it is the object of the invention to delay the need for exchanging interconnected high-power diode lasers as long as possible in the event of failure of a semiconductor laser in order to increase operating life. In order to meet this object, the electrical contacts of each semiconductor laser are connected in parallel to an electronic switching device for taking over the flow of current in the event of outage of the semiconductor laser.

Abstract: Provided is a laser diode driving circuit which prevents low optical output power of a laser diode at high ambient temperature, and prevents damage to the laser diode at low ambient temperature by adjusting the limit of a laser diode driving current, which is input to a laser diode, based on an optical output power characteristic that decreases optical output power as the ambient temperature decreases. Such a laser diode driving circuit includes a laser diode driving unit, which outputs a laser diode driving current and a laser diode protection unit, which sets the limit of the laser diode driving current output from the laser diode driving unit and increases the limit of the laser diode driving current as the ambient temperature of the laser diode increases.

Abstract: A laser driver for laser sensing system having two lasers on a single PCB, thermo-electric temperature control, rapid activation, and pulse power and duration safety tables embedded in the microprocessor controller.

Abstract: The present invention provides apparatuses and methods for measurement and control of a laser in a passive optical network. In particular, prior to receiving a transmission grant, the laser is pre-driven at a current below a predetermined threshold to “pre-charge” the laser. Also, during the zero level measurement interval, the laser is driven at a non-zero level and the required zero level current is calculated.

Abstract: A driver circuit for an opto-electrical transmitter includes a digital feedback loop. A counter in the feedback loop maintains a count that controls a bias current output to the opto-electrical transmitter. A first fault activation circuit in the driver activates a fault signal that disables the driver when the count causes an overflow or underflow. The overflow/underflow can correspond to the input range of an ADC that converts the count into an analog signal to an output amplifier or to the range of the counter. A second fault activation signal times the duration of any periods during which a digital parameter of the driver is outside a target range. The digital parameter can be e a measured monitor current or the count that controls the output amplifier.

Abstract: A safety device for a printer has a first switch and a second switch that separately determines whether a door of the printer is open or closed. When the door is open (in the state that causes danger), the safety device stops driving systems of the printer with software when the second determining device determines that the door is open and stops the driving systems with hardware when the first determining device determines that door is open. Therefore, the safety device can completely stop the driving systems.

Abstract: An improved laser system and method of operation provides signal continuity and safety in the event of accidental interruption of the laser beam. At the transmitting end, a main laser generates a beam, which is surrounded by a low powered guard beam generated by a pulsed laser. At the receiver, a leas system includes a main lens for receiving the main laser beam and a surrounding annular segmented set of lenses acting as a set of parallel receivers for the surrounding guard beam. A trigger circuit is connected to the parallel receivers. In operation, the guard beam insulates the main laser beam and detects interruptions. When the guard beam is interrupted at any point along the length of the beam, one or more of the parallel receivers will be blocked, and a signal will be generated by the trigger circuit to activate a return laser to alter the performance of the main laser, including shutdown of the beam. Upon shutdown, the current stream of bits or packets to the main laser is buffered.

Abstract: A laser diode stack includes a serially connected plurality of laser diode bars mounted on heat sinks. Connected in parallel with each laser diode is a respective safety diode which has a higher band gap than its associated laser diode. The safety diode remains nonconductive so long as the associated laser diode is operational. Should the laser diode fail in an open circuit condition, the respective safety diode responds to the open circuit voltage to restore continuity to the serially connected chan of laser diodes.

Abstract: A system and method for controlling the operating parameters of a laser diode (20) is provided. The laser control system (10) automatically optimizes the laser diode (20) operating characteristics while maintaining a safe peak power for pulse duration and pulse repetition frequency (PRF). The controlled level of output power is based on the laser diode gain determined during calibration of each laser diode projector as well as using the application of predetermined laser safety formulas. The laser control system (10) includes a laser diode (20) that is powered by a laser drive current. The laser diode (20) has a laser output having a peak power level. A detector (28) is coupled to the laser diode (20) for sensing the laser output. A laser driver (18) including a primary control loop (44) is operable, in response to the sensed laser output and a reference (43), to control the laser drive current such that the output power corresponds to the reference (43). A controller (52) is coupled to the laser driver (18).

Abstract: A low-noise current source driver for a laser diode load is achieved by means of a current-regulated supply connected across the load, and a shunt regulator. The shunt regulator comprises a shunting element, a current sensing element for sensing current conducted through the load, and an error amplifier responsive to a difference between the current sensed by the current sensing element and a first reference current. The current regulator is designed to respond to a signal a signal representative of a second reference current to produce an appropriate corresponding output current. The shunting element is connected across the power supply and load, and is controlled by the error amplifier to conduct all current from the current regulated supply in excess of the first reference current.

Abstract: In an optical supply arrangement, a laser source (10) provides transmitted laser light down an optical supply line (12, 14). A first coupler (16), remote from the laser source (10) along the optical supply line (14), taps off a small proportion of the transmitted laser light to be returned along the optical supply line (14) to a photo detector (26) driving a monitor (28) and a controller (30). If the monitor (28) detects that the photo detector (26) is experiencing a loss of return laser light, possibly due to a break in the optical supply line (14), the monitor (28) causes the controller (30) to extinguish the laser source (10) in less time than escaping laser light can cause damage to property, person or eyesight. A first embodiment has the transmitted light on a transmission fibre optic (12) and the return laser light on a separate return fibre optic (24). A second embodiment has the return laser light being sent back down the transmission fibre optic (12).

Abstract: Method and system for providing stabilization techniques for high repetition rate gas discharge lasers with active loads provided in the discharge circuitry design which may include a resistance provided in the discharge circuitry.

Abstract: A power system for a laser source comprises a plurality of semiconductor lasers or at least one laser array with plurality of independently, electrically addressable emitters. A power supply is independently connected to each of the laser emitters. A fuse device is associated with each of the laser emitters so that an electrical short of any one emitter of a laser will not cause a short to or change the power supplied to other emitters of the laser source.

Abstract: A plurality of leads (11 to 13) are secured to a stem so as to extend up and down in a state of being electrically isolated respectively, and thereby a stem (1) is formed, a laser chip (2) is provided by connecting the anode and cathode thereof with two leads on one side thereof, at least one of the anode and cathode thereof is electrically connected with one lead (11) through a wire (8) and a circumference of a laser chip (2) is covered with a cap (4) And, a chip condenser (3) is bonded between two leads (11, 12), to which an anode and a cathode of a laser chip are connected, in the other side (an exposed side not covered with a cap) of the stem not through a wire but directly with an electro-conductive agent. Therefore, a semiconductor laser with a surge protection, having a structure in which burdensome works are not required in fabricating steps and a protective condenser may surely absorb a surge when it enters, and an optical pickup using it can be obtained.