Abstract: A surface emitting laser apparatus includes an arithmetic processing unit including an I/O unit for externally inputting an instruction and a core unit that performs an operation based on the instruction and outputs a differential voltage signal modulated with a predetermined amplitude according to a result of the operation, capacitors respectively arranged on output paths of the differential voltage signal, and a surface emitting laser device that is directly connected to the arithmetic processing unit via the capacitors. An I/O voltage and a core voltage are externally supplied to the I/O unit and the core unit, respectively. The arithmetic processing unit generates a driving voltage signal by superimposing the differential voltage signal with the core voltage commonly supplied as a bias voltage without stepping up or down the core voltage and without amplifying the differential voltage signal and supplies the driving voltage signal to the surface emitting laser device.

Abstract: A method for deriving precise control over laser power of an optical pickup unit (OPU) includes: providing an analog-to-digital converter (ADC) within an automatic power calibration (APC) circuit to derive a path gain and/or a path offset from the APC circuit; and selectively performing compensation according to the gain and/or the path offset, in order to maintain precision of a relationship between the laser power and a target command utilized for controlling the laser power. An associated APC circuit comprising an ADC and at least one compensation module is further provided. The ADC is utilized for deriving a path gain and/or a path offset from the APC circuit. The compensation module is utilized for selectively performing compensation according to the path gain and/or the path offset, in order to control the laser power by a target command.

Abstract: Provided is a method for controlling a laser oscillator. Such a laser oscillator is applicable to a laser processing machine and includes a plurality of oscillator modules each adapted to be driven to oscillate a laser beam. Also, such a laser oscillator is configured to collect laser beams oscillated by driven modules for output. The method includes determining the number of modules to be driven, of the plurality of oscillator modules.

Abstract: A laser control device comprises a driver circuitry for supplying a drive current to a laser diode (LD). The device further comprises a digital storage for storing drive current values for a plurality of temperature conditions, and a central processing unit coupled to the digital storage for controlling the driver circuitry in accordance with the drive current values from said digital storage. The central processing unit is configured for multiple updating the drive current values stored in the digital storage.

Abstract: A LED control circuit and method determine the frequency and duty of a LED driving signal according to a swing control signal and a dimming control signal, respectively. Responsive to the swing control signal, a pulse edge generator generates a clock whose frequency is determined by the swing control signal. Responsive to the clock and the dimming control signal, a duty ratio controller generates the LED driving signal whose frequency is determined by the clock frequency and whose duty is determined by the dimming control signal.

Abstract: A correction circuit includes: a temperature rise derivation section which derives a temperature rise amount of a first channel of a multi-channel surface-emitting laser array due to the heating by at least one or a plurality of second channels adjacent to the first channel out of all channels included in the laser array; and a first correction section which corrects a waveform of an electric current pulse which is output from an electric current source capable of independently driving the laser array for each channel, to the first channel, based on the temperature rise amount derived by the temperature rise derivation section.

Abstract: A digital-to-analog (DA) converter includes: an analog output section that generates an output current corresponding to a value of a digital signal in response to a bias voltage and outputs an analog signal which is obtained from the output current by current-to-voltage conversion; a current source; a current control section that converts a current from the current source to a voltage signal and outputs the voltage signal as the bias voltage; and a sample and hold circuit section that samples and holds the bias voltage from the current control section and supplies the held bias voltage to the analog output section.

Abstract: A semiconductor optical amplification module that can suppress ringing without increasing power consumption or circuit size or inhibiting high-speed operation. A semiconductor optical amplifier outputs an optical signal inputted according to driving current outputted from a drive circuit. A diode is connected in parallel with the semiconductor optical amplifier. As a result, it becomes possible to suppress ringing without connecting a large resistor to the drive circuit.

Abstract: A first transistor produces a first voltage in response to a first current signal. A first resistor is coupled between the first transistor and a low voltage supply. A transconductor has a first input receiving the first voltage and producing a second current signal in response to differences between signals received on the first input and a second input. A second transistor is coupled to the second input and produces a third current signal in response to the second current signal. A third transistor, coupled to the second transistor and the second input, produces an output current signal in response to the third current signal. The first transistor is scaled to the third transistor by the inverse of a gain factor. A second resistor is coupled between the third transistor and a low voltage supply. The first resistor is scaled to the second resistor by the gain factor.

Abstract: A laser diode element assembly includes: a laser diode element; and a light reflector, in which the laser diode element includes (a) a laminate structure body configured by laminating, in order, a first compound semiconductor layer of a first conductivity type made of a GaN-based compound semiconductor, a third compound semiconductor layer made of a GaN-based compound semiconductor and including a light emission region, and a second compound semiconductor layer of a second conductivity type made of a GaN-based compound semiconductor, the second conductivity type being different from the first conductivity type, (b) a second electrode formed on the second compound semiconductor layer, and (c) a first electrode electrically connected to the first compound semiconductor layer, the laminate structure body includes a ridge stripe structure, and a minimum width Wmin and a maximum width Wmax of the ridge stripe structure satisfy 1<Wmax/Wmin<3.3 or 6?Wmax/Wmin?13.3.

Abstract: An optical-pickup apparatus includes: a first laser light source including a first laser diode to emit a laser beam having a first wavelength, and a back-monitor photodetector to receive the laser beam emitted in a backward direction, not being an optical-disc direction, and output a first monitor signal; a second laser-light source including a second laser diode to emit a laser beam having a second wavelength; a light-receiving circuit including a front-monitor photodetector to receive the laser beam emitted in a forward direction, being the optical-disc direction, and output a second monitor signal, and a switch circuit to be inputted with the first and second monitor signals, and output the first or second monitor signal according to a switch signal; and first and second drive circuits to drive the first and second laser diodes according to the first and second monitor signals outputted from the light-receiving circuit, respectively.

Abstract: A method or algorithm to control a driving current supplied to a semiconductor laser diode (LD) is disclosed. the method first prepares the look-up-table (LUT) that stores a set of parameters, ? and ?, for evaluating the modulation current Im by the equation of Im=?×Ib+?, where Ib is determined by the auto-power-control (APC) loop. In a practical operation of the LD, the APC loop determines Ib, while, Im is calculated according to the equation above by reading above two parameters corresponding to the current temperature of the LD from the LUT.

Abstract: A directly driven laser includes multiple contacts, with at least one of the contacts for injecting current into the laser such that the laser reaches at least a lasing threshold and at least one of the contacts for providing a data signal to the laser. In some embodiments a differential data signal is effectively provided to a front and a rear section of the laser, while lasing threshold current is provided to a central portion of the laser.

Abstract: A laser diode drive circuit includes: a duty control amplifier (23) that controls the duty ratio of a main signal for laser control in accordance with a duty control signal; and an AND gate (22) that outputs the duty control signal to the duty control amplifier (23), and outputs a duty control signal that controls the duty ratio of the main signal to be 0% in the duty control amplifier in accordance with a shutdown signal of a laser diode. With this structure, there is no need to input the main signal having the duty ratio controlled to a logic circuit that becomes unstable. Thus, outputs from a semiconductor laser can be shut down, and the output duty can be controlled in a stable manner.

Abstract: The present invention provides a technology called Pulse-Multiline Excitation or PME. This technology provides a novel approach to fluorescence detection with application for high-throughput identification of informative SNPs, which could lead to more accurate diagnosis of inherited disease, better prognosis of risk susceptibilities, or identification of sporadic mutations. The PME technology has two main advantages that significantly increase fluorescence sensitivity: (1) optimal excitation of all fluorophores in the genomic assay and (2) “color-blind” detection, which collects considerably more light than standard wavelength resolved detection. Successful implementation of the PME technology will have broad application for routine usage in clinical diagnostics, forensics, and general sequencing methodologies and will have the capability, flexibility, and portability of targeted sequence variation assays for a large majority of the population.

Abstract: A driver device for a laser includes a control device configured to generate a control current, an NPN differential amplifier connected to the control device and configured to superimpose a modulation current onto the control current to generate a combined current, and a laser activation switch coupled to the output of the NPN differential amplifier, the laser activation switch operating the laser utilizing the combined current. Also described herein is a communication system including a driver device.

Abstract: A semiconductor device includes an internal circuit to perform a predetermined function at a plurality of different supply power voltages, a power supply voltage region detector to detect a supply power voltage to output a detection signal, a latch to store the signal output from the power supply voltage region detector and output the stored signal as a power supply voltage region signal, and a reset circuit to generate a reset signal to perform a predetermined reset operation on the internal circuit. The latch stores the output signal from the power supply voltage region detector just after the reset operation for the internal circuit is released, and the internal circuit changes an internal setting according to the power supply voltage region signal output from the latch.

Abstract: The radiance of a laser is a function of drive current. The radiance is also a function of other factors, such as age and temperature. A laser projection device adjusts laser drive parameters using a gradient descent operation. The device parameters may be adjusted iteratively and periodically. The period may be shorter or longer than a scan line in a video image.

Abstract: A LED control circuit and method generate a high frequency clock signal with a fixed duty for a LED driver, to supply a switching current to drive a LED to emit light flashing at a modulated high frequency and with a fixed duty. By controlling the flashing LED light within certain flashing frequency range, the circuit and method allow a LED light source for expelling, confusing or trapping insects but serving only an illuminative or decorative purpose to human eyes, due to the difference between human beings and insects in visual perception of flashing frequencies.

Abstract: An optical transmitter includes a light-emitting device and an optical modulator that modulates light output from the light-emitting device by using an input signal. The optical transmitter includes a drive current switching controller that performs an ON/OFF switching control of a drive current of the light-emitting device, by using an ON/OFF signal as an input that controls ON/OFF of an optical output of the light-emitting device, in response to a switching of the ON/OFF signal. The optical transmitter also includes a drive current adjusting and generating unit that detects an ambient temperature, and generates a drive current that is adjusted according to the ambient temperature detected thereby. The drive current switching controller includes a differential circuit that is supplied a drive current that is generated by the drive current adjusting and generating unit and controls the drive current that is output to the light-emitting device, according to the ON/OFF signal.

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: The present patent application provides a low power consumption pump driving circuit including a laser cooling chip, a PMOS transistor, a NMOS transistor, a LC filter circuit, a laser, and a voltage sampling circuit. The pulse width modulating signal generated by the laser cooling chip and the control terminal of the PMOS transistor are connected to the gate of the PMOS transistor. The source of the PMOS transistor is connected to a power supply. The drain of the PMOS transistor is connected to the LC filter circuit. The other terminal of the LC filter circuit is connected to the anode of the laser. The cathode of the laser is connected to the drain of the NMOS transistor. The source of the NMOS transistor is connected to the ground. One terminal of the voltage sampling circuit is connected to the laser. The other terminal of the voltage sampling circuit is connected to the laser cooling chip.

Abstract: Two excimer lasers have individual pulsing circuits each including a storage capacitor which is charged and then discharged through a pulse transformer to generate an electrical pulse, which is delivered to the laser to generate a light pulse. The time between generation of the electrical pulse and creation of the light pulse is dependent on the charged voltage of the capacitor. The capacitors are charged while disconnected from each other. The generation of the electrical pulses is synchronized by connecting the capacitors together for a brief period after the capacitors are charged to equalize the charging voltages. The capacitors are disconnected from each other before they are discharged.

Abstract: The present invention comprises, in various embodiments, systems and methods for shutting down a laser system in an intelligent and flexible manner. An intelligent laser interlock system includes both hardwired components, and intelligent components configured to execute computing instructions. The hardwired components and the intelligent components are configured to shutdown the laser system to one or more alternative shutdown states in response to one or more interlock signals.

Abstract: A diode-laser is driven by a modulated voltage through a voltage-to-current converter. The modulated voltage has a fixed level determined by an applied fixed bias voltage and a variable level determined by a modulation voltage signal varying between minimum and maximum values. The fixed voltage level corresponds to a threshold level above which the diode-laser would provide laser-output. The modulation voltage signal is monitored and compared with a predetermined set value. If the monitored voltage signal falls below the set value, the modulated voltage is disconnected from the voltage-to-current converter and the output of the diode-laser falls to zero.

Abstract: Briefly, in accordance with one or more embodiments, a scanner for a scanned beam display may comprise a scanning platform having a mirror disposed thereon to reflect a beam of light impinging on the mirror, a drive coil disposed on the scanning platform to scan the reflected beam of light in response to a drive current applied to the drive coil. The drive coil has coil winding segments having a narrower width in one or more regions of the drive coil, and has coil winding segments having a greater width in one or more other regions of the drive coil to provide a the drive coil with a reduced electrical resistance.

Abstract: A laser device includes a semiconductor laser, a signal generating circuit generating a pulse signal for driving the semiconductor laser, an amplifying circuit amplifying the pulse signal, and a control circuit unit provided between the amplifying circuit and the semiconductor laser and controlling the pulse signal by letting alternating-current components of the pulse signal pass through and removing at least part of direct-current components of the pulse signal.

Abstract: Embodiments provide systems, devices, and methods for controlling a laser. The system includes a controller to control a laser, a ramp generator to ramp down laser power, the ramp generator electrically coupled with the controller and coupleable with the laser, and a hardware protection system electrically coupled with the ramp generator, wherein the ramp generator monitors signals sent from the controller and the hardware protection system to the ramp generator to detect signal failure and ramps down the laser power upon signal failure detection. The method includes sending a control status signal from a controller for a laser to a ramp generator, monitoring the control status signal for missing pulses, sending a hardware interlock status signal from a hardware protection system to the ramp generator, monitoring the hardware interlock status signal for signal failure, and ramping down laser power upon detection of missing pulses or signal failure.

Abstract: An optical transceiver calibration system and manufacturing method to fabricate a dual closed loop control transceiver are provided. The calibration system and method includes measuring an operating temperature and determining operational parameters based upon the operating temperature. The operational parameters may include, for example, a target power for transmitting a digital one, a target power for transmitting a digital zero, a modulation current, and a bias current. A bias may be added to the temperature to account for the difference between the temperature at the temperature sensor and the optical equipment. The operational parameters are preferably calculated independently of each other and are used as initial values during operating modes and allow the control loop to converge more quickly. The optics data is may be scanned electronically via bar code or some other electronic format prior to test. The software residing on the module then calibrates and configures the transceiver.

Abstract: There are provided an optical module including a semiconductor laser including a P-side electrode and an N-side electrode, and a semiconductor laser driver circuit that drives the semiconductor laser so as to output an optical signal from the semiconductor laser according to a pattern of a differentially transmitted digital electric signal, and the semiconductor laser driver circuit includes a positive-side terminal and a negative-side terminal for differentially transmitted non-inverted data, and a positive-side terminal and a negative-side terminal for differentially transmitted inverted data, and one terminal for the non-inverted data is electrically connected to one electrode of the semiconductor laser, and the other terminal for the non-inverted data, one terminal for the inverted data and the other terminal for the inverted data each are connected to the other electrode of the semiconductor laser.

Abstract: A semiconductor laser drive apparatus comprises a bias current setting section (232) which sets a bias current value on the basis of the drive temperature so that the temperature characteristic of the bias current value with respect to the drive temperature may be a linear function having a slope except zero and a drive current setting section (233) for setting the drive current value on the basis of the drive temperature so that the temperature characteristic of the drive current value with respect to the drive temperature may be a function having a slope except zero. The temperature characteristic of the bias current and that of the drive current are functions different from each other. With this, low cost, space-saving, and power-saving of a semiconductor laser are achieved, and a semiconductor laser drive apparatus enabling a good transmission characteristic on the reception side and a high optical output over the whole drive temperature range when driving the semiconductor laser can be provided.

Abstract: A disclosed multi-beam laser power control circuit includes a light receiving element receiving power output from semiconductor lasers to control output power of a semiconductor laser array having plural semiconductor lasers, automatic power control circuits (APC circuits) controlling emission power output from semiconductor lasers based on received corresponding automatic power control execution signals so as to be set to predetermined emission power based on output from the light receiving element, and APC execution signal input terminals inputting the corresponding automatic power control execution signals, wherein, when plural APC execution signals input to the corresponding APC execution signal input terminals are overlapped, the automatic power control circuits (APC circuits) to be preferentially operated is determined based on input timings of the APC execution signals and operated.

Abstract: A semiconductor integrated circuit device controlling a first light amount of light emitted from a light source based on a second light amount of light entering a light amount detection part so that the first light amount becomes a target level is disclosed. The semiconductor integrated circuit device includes a comparison part configured to compare a voltage corresponding to the second light amount and a reference voltage corresponding to the target level; and a drive current control part configured to control a drive current supplied to the light source based on the result of the comparison by the comparison part. The drive current control part includes a return light identification part configured to determine whether the second light amount includes a third light amount of return light occurring discontinuously.

Abstract: A laser emission device comprises a plurality of laser elements, a plurality of laser driving power supplies, optical elements which uniformize the laser light amount distributions of laser lights, plural light-receiving elements, a measurement unit which measures at least the relations between the operation current values of the laser elements and the output power values of the laser lights with respect to the operation current values, and the control unit operates the laser driving power supplies according to the operation current values and the output power values so as to make the light output powers of the laser elements different from each other.

Abstract: In a pulsed laser diode driver an energy storage capacitor is continuously being charged to a supply voltage Vr. When a pulse is initiated, energy stored in the capacitor is delivered to the laser diode load. The capacitor voltage Vd at the end of a pulse is used to control Vr to ensure that Vd is maintained above a minimum voltage Vm required to ensure operation of a current control device (such as FET) just above saturation. Test pulses (such as with attenuated currents or reduced pulsewidth) may be fired to determine an initial optimum value for Vr. After a test pulse, a slightly high estimate for Vr may be used and may be iterated (incremented) down to an optimum value Vm during a firing burst. A digital processor may be used to calculate and store data to optimize the performance. Various embodiments are disclosed.

Abstract: A light source device including a semiconductor light emitting element and a control section for controlling the semiconductor light emitting element in accordance with an input value. The control section includes a supply section that supplies the semiconductor light emitting element with a drive current based on the input value and an estimated threshold current of the semiconductor light emitting element, and an estimation section that obtains the estimation of the threshold current using the drive current and the amount of light detected to be emitted from the semiconductor light emitting element.

Abstract: An optical-switch drive circuit including a driver unit that generates, in response to a control signal, an on/off signal for driving a semiconductor optical amplifier gate switch, and a buffer unit having a high input impedance and connected between an output terminal outputting the on/off signal and the semiconductor optical amplifier gate switch. In the optical-switch drive circuit the buffer unit may include a high-resistance voltage divider that is connected with the output terminal, and an operational amplifier that buffers, and provides to the semiconductor optical amplifier gate switch, a divided voltage of the voltage divider.

Abstract: A driver circuit for an LD is disclosed. The circuit includes a decision unit, an offset adjustor, and an amplifier each having the differential configuration in an embodiment. The decision unit decides and generates a signal LOS that distinguishes the existence/absence of the input signal. The offset adjustor, depending on the signal from the decision unit, adds/compensate the offset thereof. The amplifier, whose output are pulled up to the power supply Vcc through an inductor. Because the output of the offset adjustor compensates the offset thereof during the absence of the input signal, the output of the amplifier does not cause overshoot or undershoot.

Abstract: This invention relates to opto-electronic systems using semiconductor lasers driven by optical phase-locked loops that control the laser's optical phase and frequency. Feedback control provides a means for precise, wideband control of optical frequency and phase, augmented further by four wave mixing stages and digitally stitched independent optical waveforms for enhanced tunability.

Abstract: An LD-Driver with the push-pull arrangement is disclosed. The driver includes the high side driver driven by the positive phase signal and the low side driver driven by the negative phase signal. When the positive phase signal is in HIGH, the high side driver becomes ON and the LD driver provides additional current to the bias current for the LD; while, when the negative phase signal is in HIGH, the low side driver becomes ON and the LD driver extracts a portion of the bias current for the LD.

Abstract: Apparatus and method for driving laser diodes with electrical power in pulsed operation. Pulsed power, for example using pulse-width modulation, is applied through an inductor in one or more parallel regulator circuits having little or no output capacitance to provide a high-efficiency laser-diode-driver power supply. Some embodiments that use two or more parallel regulator circuits in the laser-diode driver, drive each from a different phase of a clock signal. Some embodiments provide a first DC-to-DC converter has a relatively high-voltage input (e.g., about 275 volts, 0.75 amps) and an intermediate output of, e.g., 11 to 15 volts, 15 to 11 amps used to charge a storage capacitor, and a second DC-to-DC converter diode driver having one or more parallel circuits (each having, e.g., a PWM switching-mode controller and its respective switch, inductor, and diode) to turn on, regulate, and turn off a constant laser-diode current through one or more laser diodes.

Abstract: A light output control device for laser light sources for respective RGB colors includes, for each of RGB, three sets, each including: a semiconductor laser for one of the colors; light output detection unit for detecting a light output from the semiconductor laser; light output adjustment unit for updating a light output target value; light output control unit for controlling the semiconductor laser based on the updated light output target value; and division unit for dividing the light output by an output from the light output adjustment unit to obtain a ratio of the rising of the light output, and includes rising determination unit for determining, based on results obtained by the respective division unit, a semiconductor laser with a slowest rising and outputs light output adjustment values for the respective colors. The light output adjustment unit update their respective light output target values based on the light output adjustment values.

Abstract: In an electro-optical reader, an aiming or a scanning laser has an internal laser chip and a monitor photodiode. A controller deenergizes the chip in a deenergized state, and energizes the chip to emit a laser beam with an output power in an energized state. A positive voltage power supply forward biases and maintains the photodiode at a substantially constant positive voltage below a threshold voltage, to support a substantially constant photodiode leakage current in both states. A signal processor supports a total current comprised of a main photodiode current indicative of the output power of the laser beam in the energized state and of the leakage current which flows opposite to the main current, and removes the leakage current from the total current to output only the main current in the energized state.

Abstract: The radiance of a laser is a function of drive current. The radiance is also a function of other factors, such as age and temperature. A laser projection device adjusts laser drive parameters using a gradient descent operation. The device parameters may be adjusted iteratively and periodically. The period may be shorter or longer than a scan line in a video image.

Abstract: A optical apparatus (201) for use in an laser imaging system (200) is provided. The optical apparatus (201) includes one or more optical elements (215) that are configured to create an intermediate image plane (217) in the laser imaging system (200). A diffractive optical element (216) is then disposed at the intermediate image plane (217) to reduce speckle. The diffractive optical element (216) includes a periodically repeating phase mask (218) that can be configured in accordance with steps, vortex functions, Hermite-Gaussian functions, and so forth. Smooth grey-level phase transitional surface (337) can be placed between elements (333,334) to improve brightness and image quality. The periodically repeating phase mask (218) makes manufacture simple by reducing alignment sensitivity, and can be used to make applicable safety standards easier to meet as well.

Abstract: A laser projector for scanning a laser beam output by a multimode laser light source and displaying an image includes a laser driving unit to drive the multimode laser light source so that two-dimensional output patterns of a shape of the laser beam are different in each display frame. The laser driving unit applies to the multimode laser light source a driving waveform pattern which has the same product of an output intensity and output time of a laser light source during a display time of one dot and which includes an output intensity and output time different in each display frame.

Abstract: A fiber laser processing apparatus controls a LD drive current ILD in a power feedback control mode (FIG. 3E) such that output of a fiber laser beam FB rises substantially from zero or a value around zero to a preceding level having no substantial effect on laser processing and arrives at a desired level (PA) for the laser processing from a preceding level PB after a first time period (preceding pulse width TB) has elapsed (time point t2 of FIGS. 3A to 3F) from the start of the rising to the preceding level (time point t1 of FIGS. 3A to 3F), and this may effectively prevent occurrence of a high-peak pulse HP at the rising edge of the fiber laser beam FB (FIG. 3F).

Abstract: An optical transmitter includes a light source that outputs light superposed with a pilot signal having a predetermined frequency; an optical modulating unit that modulates the light from the light source according to an input electric signal; a detecting unit that detects a high-output-side maximum value of signal light output from the optical modulating unit, a fluctuation width of the high-output-side maximum value, and a fluctuation width of a low-output-side minimum value; a bias-potential adjusting unit that adjusts a bias potential of an electric signal to be input to the optical modulating unit based on the detected maximum value; and an amplitude adjusting unit that adjusts an amplitude of the electric signal to be input to the optical modulating unit based on the fluctuation width of the high-output-side maximum value and the fluctuation width of the low-output-side minimum value.

Abstract: A light emission device includes: first and second clad layers sandwiching an active layer; a first electrode connected with the first clad layer; and second electrodes connected with the second clad layer, at least part of the active layer forms gain areas corresponding to the second electrodes, the gain areas extend from a first side to a second side of the active layer while inclined to a vertical of the first side, at least first and second gain areas form a set of gain areas and a plurality of sets are provided, the first and second gain areas in each set are disposed perpendicular to a direction extending from the first side to the second side, the second electrodes above the first gain areas are interconnected by a first common electrode, and the second electrodes above the second gain areas are interconnected by a second common electrode.

Abstract: A system contains a laser output measurement circuit used in a laser control system (210). The circuits contain a photodiode sensor (109), sample and hold amplifier (202), IC with synchronizer and delay circuits (206), and an analog to digital converter (204). The circuits measure the laser light output (107) while the laser Module (106) transmits signals. The measurement circuit tracks and stores the laser light output (107) signal using a Photodiode Sensor (109) and with a Sample/hold (202). The methods calculate the value of the laser light output (107) from mathematical relationships, which correlate the light output (107) of the laser Module (106) to the current value of the drive signal (100). Some of the distinguishing features in the present invention are 1) feedback information from the photodiode is obtained in a synchronous manner as a snapshot of the laser performance, and 2) the measurements are precise and calibrated, and 3) no disruption of the signal transmission occurs.