Abstract: A cavity ring-down spectrometer includes: a) multiple detectors for monitoring the intensity of the radiation emitted from the cavity and the wavelength of the radiation injected into the cavity; b) controllers which turn off the radiation into the cavity and precisely adjust the temperature of, and current to, the laser gain medium; and c) means for adjusting the beam path length of the optical cavit to bring the cavity into resonance with the injected radiation. Additionally, disclosed is a method for using the spectrometer to detect a target analyte.

Abstract: A light-emitting module according to the present invention contains a Peltier element driver, and a signal processor for controlling the Peltier element driver. The Peltier element driver is mounted on a first substrate, which directly attaches to the inner bottom surface of the housing, while the signal processor is mounted on the other substrate spaced to the first substrate. The first substrate and the other substrate are vertically integrated within the housing. This arrangement enables to encase the Peltier element driver and the signal processor in the housing with effective thermal dissipation.

Abstract: A solid laser apparatus has a wavelength converter temperature controller 40 arranged for driving a Peltier device 41 to control the temperature Tc of a wavelength converter 5 so that the acceptable wavelength range of the wavelength converter 5 adapts to the wavelength range of reflected light from the grating part 6 at the temperature Ti and a laser controller 60 arranged for driving a semiconductor light amplifier device 1 to maintain the intensity of the extraordinary component passed through the polarizer 52 and measured by a photometer device 57.

Abstract: A laser machining apparatus in which laser output can be easily corrected in view of secular change of components of the laser machining apparatus and influence of temperature. Output values of a laser oscillator operated according to a reference laser output command value Psc are stored as reference output values P(?) at different temperatures ? in a table TB1. When the laser oscillator is started up, a measured output value Pr of the laser oscillator supplied with the reference command value Psc is obtained, and a new correction coefficient k is obtained to replace an old one. From a reference output value P(?) at a temperature at that time and the actual output measured value Pr, a correction value ?P is obtained and stored.

Abstract: A solid-state laser apparatus includes a cavity 17 for storing a laser diode 40 and a laser medium 6 to be excited by the laser diode 40, and a storage unit 70, for communicating with the cavity 17 and for internally storing a drying agent 71. A moisture permeable film 72 is formed at openings 73 whereat the cavity 17 and the storage unit 70 communicate with each other.

Abstract: A driving method of a semiconductor laser having an active layer region, a phase adjustment region and a distributed Bragg reflector region includes the steps of: calculating an average value of multipulse modulation currents modulated between a peak current and a bottom current input to said active layer region; calculating a difference between the average value of the multipulse modulation currents and a bias current input to the active layer region; and applying a first compensation current to the phase adjustment region when the multipulse modulation current is input to the active layer region, and applying a second compensation current corresponding to the difference to the phase adjustment region when the bias current is input to the active layer region.

Abstract: A method and apparatus are provided for monitoring an optical signal from a solid state laser. The method includes the steps of providing a planar substrate defined by opposing planar surfaces and a substrate edge that together define a substrate volume that is transparent to an optical signal from the solid state laser, disposing the solid state laser on one of the opposing planar surfaces the planar substrate such that a first portion of the optical signal travels directly through the planar substrate substantially orthogonal to the opposing planar surfaces and a second portion of the optical signal is reflected between the opposing planar surfaces of the planar substrate and passes out of the substrate through the substrate edge, and disposing an optical detector proximate the edge of the planar substrate to detect the second portion of the optical signal.

Abstract: Systems, apparatuses, and methods for driving an optical source with a current source. The optical source driver has a primary control loop having a DC—DC converter and an operational amplifier, wherein the DC—DC converter has a power input, a power output connected to the input of the optical source, and a control input, and wherein the operational amplifier has a first input connected between the optical source and the current source, a second input, and an output connected to the control input of the DC—DC converter, for controlling the output of the DC—DC converter in response to a control signal at the second input.

Abstract: An optical module having a TO-can structure is disclosed, wherein frequency characteristics have been improved in order to make high-speed transmission possible. The optical module comprising a silicon optical bench wherein a V-groove is formed, a laser diode disposed on the V-groove of the silicon optical bench, which emits light, a photo diode which receives the light and converts it into current, a stem wherein the silicon bench and the photo diode have been disposed, and a plurality of leads coupled to the stem, to provide electric signals with the laser diode and the photo diode.

Abstract: A relatively constant average optical power is provided over a user-defined range of temperatures by detecting the temperature, and adjusting the bias currents input to the laser diodes in an array of laser diodes based on the temperature and the channel loss of the channel connected to each diode.

Abstract: Embodiments of a wavelength tunable optical coupler, integrated optical components, and lasers are disclosed. The tunable optical coupler, the integrated optical components, and the lasers include thermo-optic organic material that has an index of refraction which can quickly vary in response to changes in temperature. By controlling the temperature in the thermo-optic organic material through the use of heaters or coolers, the optical coupler, the integrated optical components, and the lasers can be quickly and selectively tuned over a broad range of wavelengths with high spectral selectivity.

Abstract: A radially non-symmetric beamforming element for transforming the input energy profile of an input laser beam subject to lateral shift that is variable in radial direction and magnitude into a desired output energy profile of an output laser beam. The beam forming element includes an optical element having a profile transformation function that includes a first profile transformation function for transforming the input energy profile into the desired output energy profile and a profile correction transformation function superimposed on the first profile transformation function for modifying the first profile transformation function to correct distortions in the output energy profile introduced be a lateral shift of the input laser beam.

Abstract: The present invention has the object of offering a laser resonator capable of maintaining high amplification efficiency even if the thermal lensing effect occurring in the laser medium varies during operation or over repeated operation and suspension of the laser device. The laser resonator comprises at least a pair of reflection portions (planar reflective mirrors 3) provided such as to allow a laser beam to oscillate therebetween; a laser medium provided on the optical path of the laser between the pair of reflection portions; an excitation portion (excitation laser device 5) for exciting the laser medium; an optical system (convex lens 1) provided on the optical path of the laser beam between the laser medium and the pair of reflection portions for changing the state of the laser in the laser medium; and a movement portion for moving the optical system along the optical axis of the laser.

Abstract: The present invention is directed toward a laser wavelength locking scheme suitable for incorporation into WDM systems having channel spacings of 25 GHz or less. In a preferred embodiment, light output from the laser is supplied to a filtering element, such as an in-fiber Bragg grating or an etalon, and photodetectors are used to sense light transmitted through and either reflected by the filtering element or input to the filtering element. A measured ratio corresponding to a quotient of the photocurrents generated by the photodetectors is calculated and compared to a desired ratio corresponding to a measured temperature of the filtering element when the filtering element transmits the desired wavelength to be locked. Based on the comparison of the desired and measured ratios, a temperature error value is calculated which is used to adjust the laser temperature, as well as the laser wavelength.

Abstract: An optical transmitter includes a laser driver capable of receiving data and applying the data to drive a laser diode over a transmission line having first and second ends. The first end of the transmission line is coupled to an output of the laser driver. A first terminal of an amplifier is coupled to the second end of the transmission line. A second terminal of the amplifier is coupled to the laser diode. The signal amplitude applied at the first terminal controls optical output amplitude of the laser diode.

Abstract: A first software program for simulating an operating laser system controls a processor that generates one or more dummy parameters each corresponding to a parameter of an operating laser system. The dummy parameter is read over a same or similar signal interface as the operating laser system by a processor running a test software subroutine having the laser system parameter as an input. An algorithm including the test software subroutine then generates an output command based on the value of the dummy parameter. A second software program for efficiently scheduling laser service routines based on a predetermined lithography system schedule controls a processor that reads the lithography system schedule including scheduled system downtimes, wherein the scheduled downtimes include start times and durations. The processor then reads a time window and duration for each of one or more scheduled laser service routines.

Abstract: A laser device which may be used as an oscillator or amplifier comprising a chamber having a volume formed therein and a gain medium within the volume. The gain medium comprises solid-state elements containing active laser ion distributed within the volume. A cooling fluid flows about the solid-state elements and a semiconductor laser diode provides optical pump radiation into the volume of the laser chamber such that laser emission from the device passes through the gain medium and the fluid. The laser device provides the advantages of a solid-state gain medium laser (e.g., diode-pumping, high power density, etc), but enables operation at higher average power and beam quality than would be achievable from a pure solid-state medium.

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

Abstract: A laser gain medium having a layered coating on at least certain surfaces of the laser gain medium. The layered coating having a reflective inner material and an absorptive scattering outside material.

Abstract: The invention relates with an optical bench for optoelectronic packages comprising a rigid insulating substrate, the substrate having a top surface along which it is defined an optical axis, the substrate comprising: a device region for mounting at least an optoelectronic device in alignment with the optical axis, and a fixing region adjacent to the device region for affixing at least an optical component in alignment with the optical axis. The substrate further comprises a third region provided with metallised tracks, the third region extending over the substrate top surface along at least part of one side of the fixing region in a direction substantially parallel to the optical axis. The invention also relates with an optical bench comprising: a single baseplate having a device region and a fixing region; a welding platform mounted directly on said fixing region; a heat sink mounted directly on said device region; and an optoelectronic device directly mounted on said heat sink.

Abstract: A method of frequency and mode stabilizing a tuneable laser, wherein one or more measurable magnitudes is/are measured, wherein the laser has been characterized with respect to a number of operation points, and wherein the values of the measurable magnitude or magnitudes are stored in a microprocessor or corresponding device. The invention is characterized by causing the values of one or more of the measurable magnitudes to be non-extreme values; storing the values of such non-extreme values as a quotient where the numerator is the derivative of a measurable magnitude ?Y with respect to a control current ?I to one laser section, and where the denominator is the derivative of another measurable magnitude ?Z with respect to said control current ?I; and using the stored values to control the laser to a desired operation point.

Abstract: A problem of the present invention is to provide a semiconductor laser module for making precise temperature control possible. A semiconductor laser module 1 according to the present invention has a Peltier element 4, a thermistor 5 for detecting the temperature of the Peltier element 4, and a differential amplification circuit 6 for generating a control signal according to the detection signal from the thermistor 5 so that the surface temperature of the Peltier element 4 conforms to a set temperature. A parallel compensating circuit 12 for generating a compensating signal for compensating for a delay in temperature variation in the Peltier element 4 with respect to the input of current signal to the Peltier element 4 branches and is connected to the output portion of the differential amplification circuit 6. The compensating signal is sent to an addition circuit 9 and detection correction signal obtained by adding the detection signal of the thermistor 5 and the compensating signal is generated.

Abstract: A system is provided for nulling out or eliminating alignment errors in an optical system by moving a lens to capture and center a collimated beam laterally-shifted by thermal excursions, thus to couteract the boresight error caused by the thermally-induced lateral shifting. As a result, alignment error the thermal coefficient of expansion characteristics of the optical elements and their mounting systems caused by lateral off-sets is corrected by moving a lens or lens system in response to thermal changes in a direction which moves the lens so that the collimated light impinging on the lens is made to come in on the optical axis of the lens.

Abstract: The invention relates to a method and device for determining the output power of a semiconductor laser diode being operated with a diode current. A defined measuring current, which is less than the threshold current of the semiconductor laser diode, is conducted in a conducting direction through the semiconductor laser diode. The forward voltage drop across the semiconductor laser diode is measured, and the temperature of the laser-active region of the semiconductor laser diode is determined from the measured forward voltage by using at least one calibration curve. The invention makes a simple and precise determination of the output power possible without requiring an additional measuring device, for example, a monitor diode.

Abstract: The present invention is directed to the development of compact, coherent sources emitting in the terahertz frequency region using interface phonons. In accordance with a preferred embodiment, a semiconductor heterostructure light emitting device includes a quantum cascade structure having at least an upper lasing level and a lower lasing level. The system uses heterostructure interface phonon bands to depopulate the lower lasing level of at least a three level semiconductor device. The device includes multiple coupled quantum well modules. In alternate preferred embodiments, the device includes quantum dot layers and/or, quantum wire structures, and/or mini-bands in a superlattice, for example, GaAs/AlGaAs superlattice. The phonons in the device improve efficiency, decrease the threshold current and result in system temperatures that are as high as room temperature. The semiconductor device provides emission of terahertz radiation.

Abstract: A laser apparatus includes a semiconductor laser element having a first active layer made of a GaN-based compound, and emitting first laser light; and a surface-emitting semiconductor element having a second active layer made of a GaN-based compound, being excited with the first laser light, and emitting second laser light. In addition, the surface-emitting semiconductor element may have a first mirror arranged on one side of the second active layer, and a second mirror may be arranged outside the surface-emitting semiconductor element so that the first and second mirrors form a resonator.

Abstract: In order to obtain an optical transmitter module for converting an input electric signal to a light signal with fidelity and outputting it therefrom, a terminal resistor Rt and an optical modulator MD are connected in parallel within a package including a laser diode with a monolithically integrated optical modulator for obtaining the light signal according to the electric signal. One thereof is grounded and the other thereof is connected to a wire inductance (L1) and an impedance matching resistor Rd in series with this parallel connection. Further, a high frequency transmission line (micro-strip line) MSL for the transmission of the electric signal is connected to the other end of the impedance matching resistor Rd.

Abstract: A method and apparatus are provided for in situ protection of sensitive optical materials from alternation or damage due to exposure to trace atmospheric components, during shipping, storage or operation. The sensitive optical material is disposed within an enclosure adaptable to be substantially sealed against the external atmosphere. A container, enclosing a sink material absorbing trace atmospheric components, is coupled to the enclosure by a gas permeable surface, which allows fast diffusion of the trace atmospheric component inside the enclosure to the sink material.

Abstract: An improved optical system for scanning optical codes is disclosed. A laser beam produced thereby is a diverging, nearly diffraction free beam and may be used to produce an elongated scanning spot. A laser assembly which may be used to produce such beams and spots, combines various optical functions in structures which are relatively insensitive to temperature change.

Abstract: A photonic device has a semiconductor substrate with an active photosensitive surface generating a photocurrent dependent on the intensity of light falling on it. A light emitting element, typically a VCSEL, having a lower electrode is located on a contact element in the middle of the active surface. The light emitting element covers the contact element. A doped conductive path within the substrate establishes electrical connection between the contact element and a peripheral bonding pad. The doped path preferably constitutes the entirety of the upper layer forming the photosensitive surface.

Abstract: A method and apparatus are provided for monitoring an optical signal from a solid state laser. The method includes the steps of providing a planar substrate defined by opposing planar surfaces and a substrate edge that together define a substrate volume that is transparent to an optical signal from the solid state laser, disposing the solid state laser on one of the opposing planar surfaces the planar substrate such that a first portion of the optical signal travels directly through the planar substrate substantially orthogonal to the opposing planar surfaces and a second portion of the optical signal is reflected between the opposing planar surfaces of the planar substrate and passes out of the substrate through the substrate edge, and disposing an optical detector proximate the edge of the planar substrate to detect the second portion of the optical signal.

Abstract: A Q-switched microlaser is provided that is capable of supporting a zig-zag resonation pattern in response to pumping of the active gain medium so as to effectively lengthen the microresonator cavity without having to physically lengthen the microresonator cavity. As such, the microlaser can generate pulses having greater pulse widths and correspondingly greater pulse energies and average power levels than the pulses provided by conventional microlasers of a similar size. A corresponding fabrication method is also provided that permits a plurality of Q-switched microlasers to be fabricated in an efficient and repeatable manner.

Abstract: A method for operating an excimer or molecular fluorine laser system at a stabilized wavelength includes generating a laser beam and directing a beam portion through a wavelength measurement system, calibrating the wavelength measurement system to an absolute reference, determining the wavelength of the laser beam including figuring in a drift compensation value of the wavelength, and tuning the wavelength to a target wavelength when the determined wavelength differs from the target wavelength.

Abstract: It is an object to provide a laser apparatus, a laser irradiating method and a manufacturing method of a semiconductor device that can perform uniform a process with a laser beam to an object uniformly. The present invention provides a laser apparatus comprising an optical system for sampling a part of a laser beam emitted from an oscillator, a sensor for generating an electric signal including fluctuation in energy of the laser beam as a data from the part of the laser beam, a means for performing signal processing to the electrical signal to grasp a state of the fluctuation in energy of the laser beam, and controlling a relative speed of an beam spot of the laser beam to an object in order to change in phase with the fluctuation in energy of the laser beam.

Abstract: A semiconductor laser module according to the present invention has a semiconductor laser element for outputting a laser beam and a package hermitically containing and sealing the semiconductor laser element. The package has a vent for introducing and/or exhausting a low heat conduction type gas into or from the package. The vent is hermetically sealed by swaging and welding the external end thereof after the low heat conduction type gas has been introduced into or exhausted form the package.

Abstract: An auto laser power control circuit is provided which improves the response of the optical output level of a laser diode in accordance with variations in the operation mode. In an auto laser power control circuit for comparing a voltage corresponding to the optical output from the laser diode which emits a light in accordance with a supplied driving current with a reference voltage, and controlling the driving current so as to reduce the difference at the time of the steady operation, by controlling a switch connected between the input and output terminals of an operational unit which compares the voltage corresponding to the optical output from the laser diode and the reference voltage, the driving current to the laser diode is controlled with a smaller time constant upon the start such as a transition of from a read operation mode to a write operation mode as compared with the time of the steady operation.

Abstract: A laser package comprises a laser diode source having a first Fabry-Perot cavity between a highly reflective back facet and low reflective front facet for providing a first light output for an optical application. A light monitor is positioned adjacent to the back facet and aligned to receive a second light output from the laser diode back facet. A pigtail fiber having a lensed fiber input end is positioned from the laser diode front facet to form an optical coupling region and is aligned relative to the lasing cavity to receive the first light output into the fiber, the light output exiting the package for coupling to the application. A portion of the first light output from the lasing cavity is reflected off the lensed fiber input end with a portion directed back into the lasing cavity and another portion reflected off of the laser diode front facet.

Abstract: One optical base is provided on each side of a housing that houses a laser oscillator. Optical parts of an optical resonator are fixed to the optical bases. The optical bases are fixed to each other, independently from the housing, by supporting rods. A plate spring and two dampers fix the respective optical base to respective end of the housing. The plate spring bends in the direction of the laser beam when the housing deforms. The damper attenuates oscillation generated due to the displacement of the housing.

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 method and related apparatus for feedback control of laser power provided by a pick-up head of an optical disk drive. The pick-up head can adjust a cross-voltage of a laser generator according to a signal level of a control signal such that the laser power is changed correspondingly. The method includes updating the signal level of the control signal according to feedback of the cross-voltage or the control signal, such that the laser power is adjusted accordingly.

Abstract: A high efficiency light emitting diode (LED) driver circuit utilizes a capacitor to regulate the LED driving current. The voltage across the capacitor is monitored to maintain a preselected low threshold voltage on the capacitor, which determines the LED optical emission intensity. The capacitor provides the LED driver current by discharging through the LED during transmission intervals, and the power supply for the device is used only to maintain the capacitor charge level. The LED driver circuit accordingly operates at high efficiency with low power consumption. The LED driver current can be regulated by changing the low and high threshold voltages of the capacitor pump controller, thereby to control the optical intensity of the LED.

Abstract: A temperature compensation apparatus for controlling an output power of a laser diode according to a temperature variation of the laser diode, and a method therefor. An error voltage between a voltage corresponding to the output power of the laser diode and a reference voltage is generated. The error voltage is output as a control voltage corrected based on the output power and is applied to the laser diode. When the level of the error voltage overflows or underflows in a first up/down counter, the control voltage based on the luminous efficiency of the laser diode is output by applying the corrected control voltage to the laser diode while interlocking the first up/down counter with a second up/down counter. Accordingly, it is possible to stabilize the luminous efficiency and reduce control error of the laser diode.

Abstract: The present invention provides an edge cladding for a slab laser, the edge cladding comprising a cooling channel system therein.

Abstract: A process for the adaptive beam control of medium-energy laser weapons for fighting electro-optical sensors and windows, wherein the behavior of the laser power reflected from a bright spot of the target and measured by a thermal image apparatus during increasing irradiation intensity is analyzed during a phase of measurement. The laser power to be emitted that will lead to the desired laser beam diameter or to the highest possible laser intensity at the target during the subsequent phase of fighting is then derived by calculation from this as well as other parameters influencing the thermal beam expansion. It is thus made possible that the laser does not always have to be operated with the maximum power, but only with the currently needed power during the phase of fighting, so that a saving is achieved in the consumption of primary laser energy. One example is explained.

Abstract: The laser drive device of this invention includes a laser, first and second current sources, a current amplifier, and first and second transistors. When the first transistor is OFF, a first current from the first current source is supplied to the current amplifier, where the current is amplified to generate a laser current to be supplied to the laser. Thus, the laser is turned ON. During this time, the second transistor is ON, allowing a second current to flow from a power supply node into the second current source. When the first transistor is ON, the entire or part of the first current flows into the second current source through the first transistor. This reduces the current supplied to the current amplifier and thus the laser current, resulting in turning OFF the laser. During this time, the second transistor is OFF. The values of the first and second currents are determined by a set current value.

Abstract: A modulating electric current and a bias electric current supplied to a semiconductor laser can be respectively changed correspondingly with ambient temperature even in a burst mode, and the level of an optical output is constantly set at all times irrespective of the ambient temperature.

Abstract: It is an object to provide a laser apparatus, a laser irradiating method and a manufacturing method of a semiconductor device that make laser energy more stable. To attain the object, a part of laser beam emitted from an oscillator is sampled to generate an electric signal that contains as data energy fluctuation of a laser beam. The electric signal is subjected to signal processing to calculate the frequency, amplitude, and phase of the energy fluctuation of the laser beam.

Abstract: A laser system includes a high reflector and an output coupler that define a laser oscillator, which produces a fundamental beam. A harmonic generator is positioned to receive at least a portion of the fundamental beam and produce a harmonic beam. The harmonic generator is configured to operate at a temperature selected to provide a least amount of change of a selected parameter of the harmonic beam for the longest period of time. Harmonic beam parameters can include the size and location of the harmonic beam waist, and the divergence of the harmonic beam.

Abstract: The invention relates to an improved method and system for synchronizing signals in a particle accelerator system. In one embodiment, a method and system is disclosed whereby a phase of laser pulses are monitored, and a high-frequency signal is adjusted as necessary to be substantially in-phase with the laser pulses. In another embodiment, a method and system is disclosed whereby a phase of an electromagnetic field in an electron gun is monitored, and a high-frequency signal is adjusted as necessary to be substantially in-phase with the electromagnetic field.

Abstract: A photonic device has a semiconductor substrate with an active photosensitive surface generating a photocurrent dependent on the intensity of light falling on it. A light emitting element, typically a VCSEL, having a lower electrode is located on a contact element in the middle of the active surface. The light emitting element covers the contact element. A doped conductive path within the substrate establishes electrical connection between the contact element and a peripheral bonding pad. The doped path preferably constitutes the entirety of the upper layer forming the photosensitive surface.