Abstract: A laser driver outputs a data protocol signal as controlled by an extinction control signal. The data protocol signal has a header including first and second bit patterns. A laser outputs an optical signal in response to being excited by the data protocol signal. The first and second bit patterns are measured and used to calculate an extinction ratio. The calculated extinction ratio is compared with a desired extinction ratio to generate the extinction control signal.

Abstract: A semiconductor laser optical output control circuit able to precisely control an optical output of a semiconductor laser, provided with a peak value detection circuit 106-1 and a bottom value detection circuit 107-1 for detecting the output of a photo-diode PD 102, optical power setting voltage sources 105-1 and 105-2 for giving the setting value of the optical output of a semiconductor laser LD 101, a peak value detection circuit 106-2 and a bottom value detection circuit 107-2 for detecting the output of a switching circuit 104 for switching the setting value, error amplifiers 108-1 and 108-2 for comparing the detected outputs of the peak value detection circuit 106-1 and peak value detection circuit 106-2 and the bottom value detection circuit 107-1 and bottom value detection circuit 107-2, and a switching circuit 110 for switching the comparison results of the error amplifiers 108-1 and 108-2 and supplying the same to a current amplifier 111 in synchronization with the switching circuit 104.

Abstract: Circuits and methods for automatically controlling lightwave emitters are provided. A control system is provided that includes a variable gain circuit for automatically adjusting the gain of a control signal with respect to a feedback signal, a modulation signal, and a reference signal. This allows the optical output of the lightwave emitter to remain substantially constant despite changes in transfer ratio due to aging or temperature variations. Furthermore, in some embodiments, a user may select the overall gain of the system to optimize response time, bandwidth, or steady-state accuracy.

Abstract: An integrated wavelength combiner/locker is described herein that performs a multiplexing function of a wavelength combiner and a wavelength error measurement function of a wavelength locker. In the preferred embodiment, the integrated wavelength combiner/locker includes a filter (e.g., diffraction grating, glass plate) that receives multiple optical signals and outputs a multiplexed optical signal. The integrated wavelength combiner/locker also includes a partially reflective device (e.g., mirror, coupler/circulator) that directs a portion of the multiplexed optical signal back into the filter that splits the multiplexed optical signal back into individual optical signals. The integrated wavelength combiner/locker further includes one or more ordered pairs of photodetectors each of which receives one of the individual optical signals and is used to detect a wavelength error in that optical signal.

Abstract: A laser driver for generating drive waveforms that are suitable for driving a single VCSEL or an array of VCSELs. A digital controller is integrated into the laser driver and is utilized to initially program and selectively adjust during the operation of the driver one or more of the following VCSEL drive waveform parameters: (1) bias current, (2) modulation current, (3) negative peaking depth, and (4) negative peaking duration. The laser driver has an aging compensation mechanism for monitoring the age of the laser and for selectively adjusting the dc and ac parameters of the VCSEL drive waveform to compensate for the aging of the laser. The laser driver also has a temperature compensation mechanism for monitoring the temperature of the driver IC and selectively adjusting the dc and ac parameters of the VCSEL drive waveform to compensate for the changes in temperature.

Abstract: According to the present invention, there is provided a solid-state laser diode comprising: a laser diode for exciting a solid laser medium; a constant current source for supplying a constant current to the laser diode; voltage measurement unit for measuring a voltage at both ends of the laser diode; and abnormality detection unit for detecting an abnormality at the laser diode based on an output of the voltage measurement unit. Whereby a photodiode need not be arranged on the periphery of the solid laser medium and the laser diode, and an abnormality at the laser diode can be detected without increasing the size of the device and complicating the device and without deteriorating the laser emission efficiency.

Abstract: A photonic device including an array of lasers providing light to an array of electro-absorption modulators, both on a common substrate. In some embodiments the lasers are in a closely spaced array and lase at different wavelengths, providing with associated electro-absorption modulators a compact wavelength selectable laser.

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: The present invention is directed to a system and method which provide a Raman pump which is spectrally tailored in response to feedback from control structure associated with the Raman pump source. In certain embodiments of the present inventions, an incoherently beam combined laser (IBC) is utilized to provide a spectrally tailored Raman pump. In these embodiments, emitters in an emitter array are either individually addressable or block addressable to facilitate adjustment of emitter output power. By adjustment of the output power, the Raman pump may be spectrally tailored. The spectral tailoring can occur by employing suitable control algorithms to algorithms to dynamically maintain reasonably flat Raman gain.

Abstract: A tunable optical local oscillator is used for optical heterodyne signal detection using an electrooptic Mach-Zehnder modulator to produce a rapidly tunable optical signal from a tunable RF frequency generator. A combination of the Mach-Zehnder modulator and optical fibers for providing stimulated Brillouin scattering are used to suppress unwanted signals for providing a spectrally pure optical local oscillator waveform. Suppression of unwanted optical signals, up to 50 dB, generated by the Mach-Zehnder modulator is obtained, resulting in high spectral purity of the optical local oscillator waveform with an extended tuning range of the tunable optical oscillator equal to the operating bandwidth of up to 60 GHz of the Mach-Zehnder modulators.

Abstract: An apparatus for and a method of controlling an output of a laser diode in an optical recording/reproducing apparatus. The apparatus includes a sampling circuit sampling a present power value output from the laser diode with a predetermined frequency, an arithmetic unit connected to the sampling circuit, outputting a control power value applied to the laser diode in response to the present power value output from the sampling circuit and a reference power value, and a controller connected to the sampling circuit and the arithmetic unit, generating control signals, which control the operations of the sampling circuit and the arithmetic unit.

Abstract: A laser control circuit comprises a temperature control circuit and a data processing circuit. The temperature control circuit adjusts the temperature of a laser diode by controlling a temperature regulator. The data processing circuit receives the output of a wavelength monitor. The data processing circuit first adjusts the, temperature of the laser diode to a temperature value previously associated with the target wavelength. Then the data processing circuit finely adjusts the temperature of the laser diode according to the output of the wavelength monitor. Because rough adjustment has been carried out, it is not necessary to change the wavelength significantly according to the output of the wavelength monitor. Therefore, the periodic wavelength dependence of the output of the wavelength monitor does not decrease the accuracy of the control.

Abstract: A semiconductor laser source includes a laser diode having front and rear facets. The laser diode includes a substrate and a lower cladding layer disposed on the substrate. The lower cladding layer is doped with a dopant of the first conductivity type. An active layer is disposed on the lower cladding layer and an upper cladding layer is disposed on the active layer. The upper cladding layer is doped with a dopant of the second conductivity type. At least one electrode is disposed on a first outer layer of the diode. A pair of electrodes is disposed on a second outer layer of the diode. The second outer layer is located on a side of the diode opposing the first outer layer. The pair of electrodes is configured to allow application of different currents to each one of the electrodes in the pair of electrodes. A reflector, which is located external to the laser diode, is in optical communication with the front facet of the laser diode for providing optical feedback to the active region.

Abstract: A laser used in a DWDM optical-fiber application is controlled so that, before it is powered up or down, its output power is maximally attenuated, the result being minimal cross-channel interference due to out-of-spec. wavelength. Laser control is further characterized by the steps of: (a) with laser current at zero, establishing a desired temperature of operation of the laser; (b) with output attenuation at maximum, increasing the current and regulating it to a level at which the design operating wavelength is achieved, and (c) decreasing the attenuation until the desired output power to the optical-fiber link is attained. Maximum attenuation is preferably applied during step (a).

Abstract: The present invention provides a laser machining apparatus in a simple structure which can properly carry out laser machining by irradiating a laser beam easily at a predetermined energy density to a machining-target site in a predetermined range, and in addition, which can be downsized and can be kept with easy maintenance and has enhanced durability. The apparatus includes: a semiconductor stack 1 comprising a plurality of semiconductor laser elements; and a controller for controlling emission of the laser beam emitted from each of the semiconductor laser elements. The semiconductor stack 1 is divided into a plurality of blocks B11, B12, B13, B14 in correspondence with the machining-target site of a work piece. The controller controls the irradiation of the laser beam from each of the blocks B11, B12, B13, B14 to be changeable in terms of time.

Abstract: Techniques and designs for tunable and dynamically stabilized a laser wavelength in various lasers, including fiber lasers and actively mode-locked lasers. In an actively mode-locked laser, a dynamic wavelength tuning control and a dynamic cavity length control are implemented to maintain mode locking during tuning of the laser wavelength.

Abstract: In a power supply circuit, a first power-supply voltage supplied to a laser driving circuit for driving a short-wavelength semiconductor laser of an optical pickup is made higher than a second power-supply voltage supplied to circuits except the laser driving circuit, for example, a reproducing system, a servo system and a recording system. Thus, the power consumption in a device for driving a short-wavelength semiconductor laser such as an InGaN-based semiconductor laser is reduced.

Abstract: A dithering signal is superimposed on a laser frequency control signal. In this way, laser frequency control may be achieved by employing measurements from a single photodetector. By sampling synchronously to the dithering signal, it is possible to generate both the magnitude end sign of the current frequency error based on the output of a single photodetector. This reduces the number of components required to generate an optical signal and is particularly advantageous in WDM systems where laser frequency control components may be duplicated over a large number of channels.

Abstract: Tunable laser systems use servo control loops to control and monitor laser parameters such as channel, temperature, and power. The many control loops operate asynchronously, which means that noise generated by input sampling and/or output updating from one or more loops could interfere with the sampled inputs of one or more of the other loops. Embodiments of the present invention synchronize setting and sampling of tunable laser parameters to reduce noise. Noise that is related to synchronized setting and sampling of tunable laser parameters allows the noise to be reduced to constant offsets to be compensated for in the laser parameters of interest.

Abstract: Conventionally, in the wavelength locking optical system, the wavelength as detected is deviated from a targeted range owing to the change of the peripheral temperature resulting from the temperature characteristics of the wavelength error detection device. To solve this prior issue, it is arranged such that a portion of the wavelength error detection device, through which portion light-beams passes, contacts a material of high heat conductivity.

Abstract: An optical transmission system is provided, which permits high-precision optical transmission of a signal even if the signal has a high accurate timing, an indefinite period, and a DC component. The transmitting side is provided with a rise edge detecting circuit 1 for detecting the rise edge of a transmitting signal waveform, a transmitting pulse generating circuit 2 for generating a transmitting pulse signal (b) constituted by a pair of opposite-polarity pulses inverting their polarities at the detected timing, and a light intensity modulation circuit 3 for generating a light intensity modulated signal (c) based on the pulse signal (b). The receiving side is provided with an AC-coupled receiving circuit 4 for receiving the light intensity modulated signal (c) and extracting therefrom only an AC component, and a discrimination circuit 5 for discriminating the rise timing from the received signal.

Abstract: Systems and methods for probing or evaluating optical loss characteristics associated with lasers by monitoring voltage across a laser gain medium, and a laser and method of laser operation wherein intra-cavity losses are determined by monitoring voltage across a gain medium and wherein the cavity loss profile is adjusted according to the voltage across the gain medium.

Abstract: The invention provides a ≧4 kHz repetition rate argon fluoride excimer laser system for producing an UV wavelength 193 nm output. The ≧4 kHz repetition rate argon fluoride excimer laser system includes an argon fluoride excimer laser chamber for producing a 193 nm discharge at a pulse repetition rate ≧4 kHz. The ≧4 kHz repetition rate argon fluoride excimer laser chamber includes magnesium fluoride crystal optic windows for outputting the 193 nm discharge as a ≧4 kHz repetition rate excimer laser 193 nm output with the magnesium fluoride crystal optic windows having a 255 nm induced absorption less than 0.08 Abs/42 mm when exposed to 5 million pulses of 193 nm light a fluence ≧40 mj/cm2/pulse and a 42 mm crystal 120 nm transmission of at least 30%.

Abstract: A method of controlling a tuneable laser that has been characterized with respect to one or more suitable laser operation points. Each operation point is determined by the manner in which the different laser sections are controlled, in order to operate the laser at a predetermined operation point. The voltage across the different laser section is determined for different operation points when controlling the laser, and the voltages across the different laser sections are held constant when the laser is in operation to maintain a predetermined operation point.

Abstract: A method and apparatus for driving a laser diode source, such as a laser diode or a laser diode array. The driver controlling current in response to a signal indicative of excessive current or current density. The signal may be derived from the drive current, the voltage across the laser diode source or the impedance of the laser diode source. The circuit may be pulsed using a switch, such as a GCT. The current to generate drive the laser diode source provided by a capacitive or inductive charging circuit.

Abstract: A light frequency locker (10) able to accept a light beam (14) generated by a controllable light source (12) into a light diverter (16) and impart to it a transverse displacement characteristic which can be detected in a light detection unit (20) connected to a processor (22). The processor (22) then controls the light source (12). Optionally, a light diverger (18) may be provided to enhance angular resolution. The light diverter (16) and the light diverger (18) may either transmit or reflect the light. The light diverter (16) may particularly include a diffraction grating (116, 156), Fabry-Perot interferometer (216), multiple slit plate (316), or an acousto-optical unit (416).

Abstract: A wavelength stabilized laser module is provided which is so configured as to be simplified and smaller in size and is capable of emitting semiconductor laser light whose wavelength is stablized with high accuracy. The wavelength stablized laser module includes a semiconductor laser, a substrate, a lens to convert emitted semiconductor laser light to parallel luminous flux, a first photoelectric converter to receive a part of the parallel luminous flux and to convert it to electric signals, a filter to receive a part of the parallel luminous flux, a second photoelectric converter to receive light transmitted through the filter and to convert it to electric signals, wherein a control signal to be used for stabilization obtained by computations of electric signals fed from the converters is fed back to the semiconductor laser device and/or the substrate so that said semiconductor laser is able to stably emit laser light having a reference wavelength to be used as a target for stabilization.

Abstract: A laser survey instrument includes a laser source; a beam waist position varying optical system having a movable lens group through which a laser beam emitted from the laser source passes, so that the movement of the movable lens group in an optical axis direction causes the beam waist position of the laser beam to vary; a rotatable head portion from which the laser beam transmitted through the beam waist position varying optical system is emitted; a reciprocating-scan angle setting device for setting a reciprocating-scan angle of the rotatable head portion in accordance with position data of the movable lens group of the beam waist position varying optical system; and a head portion controller for reciprocally moving the head portion by the reciprocating-scan angle.

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 apparatus and method for flexibly and precisely varying temporal placement and duration of pulses, within a train of high speed, high power optical pulses. The invention includes optics adapted for focusing on a layer of an information storage media. An optical pulse generator is coupled with the layer through the optics for generating a train of optical pulses, wherein each pulse has a respective temporal placement within the train and has a respective pulse duration. The respective pulse duration of each pulse is controlled by an amount of an analog duration control voltage, in accordance with a WRITE STRATEGY, which is based on a physical property of the layer of the information storage media. Similarly the respective temporal placement of each pulse is controlled by an amount of an analog temporal placement control voltage, in accordance with the WRITE STRATEGY.

Abstract: A voltage clamp transistor 12 has a main current path (i.e., drain-source path or emitter-collector path) serially connected to the output terminal 9 of a drive IC 1, and also has a control electrode (i.e., gate or source) with a predetermined voltage applied thereto. An optical modulator 10 of a laser diode or the like is connected either directly or via an AC-coupled capacitor to the output side of the transistor 12.

Abstract: A method and a system for filtering a user light beam using a periodic filter having a frequency response stabilized at an absolutely calibrated value are provided. A primary light beam is generated by a tunable laser source and portions thereof are filtered by an absolute reference filter and the periodic filter. First the frequency of the laser source is automatically locked on the absolute reference filter, and then the frequency response of the periodic filter is locked relative to the frequency of the laser source. The frequency response of the periodic filter is therefore continuously maintained at the proper calibration. User input and output are provided to pass the user light beam through the stabilized periodic filter independently of the filter stabilization process. A broadband absolutely calibrated optical source and a method for absolutely calibrating an optical spectrum analysis device are also provided.

Abstract: A digital laser driver circuit is provided in which a digital synthesizer synthesizes a modulation index signal for precisely setting the modulation level of the laser, and a pair of feedback loops control the average power level and modulation index of the laser diode. The laser diode includes a back-facet photodiode that is used to monitor the laser's average and peak optical power levels. The average power level is measured by an analog feedback loop and compared to an externally supplied reference voltage in order to maintain the laser at a particular average optical power level. The peak power is measured by a digital feedback loop and compared to a pair of threshold levels based on a ratio of the average power level using digital comparators. The comparators provide signals to the digital synthesizer in order to indicate that the modulation level is too low or too high.

Abstract: A large area slab laser, wherein disharge is confined between two large area electrodes. A two dimensional array of inductors is placed across the electrodes so that the standing wave patterns associated with the propagation of the high frequency driving current are corrected. In one embodiment, the electrodes are planar, in another, the electrodes are annular.

Abstract: The invention discloses an optical output power and output wavelength control system for use with a sampled grating distributed Bragg reflector (SGDBR) laser. The optical output power and output wavelength control system for use with a sampled grating distributed Bragg reflector (SGDBR) laser comprises a controller for providing current inputs to the laser controlling the optical output power and output wavelength and an external reference receiving an optical output from the laser and providing a reference output to the control, wherein the controller compares the optical output power and output wavelength of the laser to the reference output and locks the optical output power and output wavelength of the laser to the external reference.

Abstract: A drive circuitry that drives a vertical cavity surface emitting laser is provided. The drive circuitry includes a modulator, a negative peak timer and a limiter. The negative peak timer causes the modulator to rapidly decrease the magnitude of the output signal of the modulator to dissipate charge stored on the laser. Thus, the vertical cavity surface emitting laser quickly turns off.

Abstract: A laser power control circuit utilized in a laser scanner that comprises lasers for forming latent images on a photosensitive drum is provided. The laser power control circuit controls the laser emitting power of a multi-laser diode which has two laser diodes and one photo diode for monitoring the laser power. The photo diode simultaneously receives laser beams emitted from each of the laser diodes and outputs an output signal in response to the received laser power. The laser power control processor alternately controls the laser emitting power of each of the laser diodes for each time period which is assigned to each of the lasers. The laser emitting power of the laser diodes is controlled in accordance with the output signal from the photo diode.

Abstract: A light source with a broadband frequency-periodic output spectrum for digital spectrally coded data, whereby the light source consists of a solid state laser that is frequency-modulated or phase-modulated within one bit period.

Abstract: A compact, low-cost semiconductor laser driving apparatus which can assuredly prevent the influence of mode-hopping noise, a semiconductor laser driving method and an image forming apparatus are provided. Automatic Temperature Control and Automatic Power Control are performed and then the temperature of a laser diode (LD) is raised in small increments (0.1° C.). At each temperature level, the LD is driven in accordance with predetermined image data and an LD light amount is detected for each of a predetermined number of image lines. When the proportion of these line light amounts that are outside a range of tolerance is less than a predetermined proportion (5%) for a predetermined number of consecutive temperature levels, the temperature is stored to serve as a control temperature of the LD during actual optical scanning. This process is performed for all LDs.

Abstract: An electronic driver circuit for directly modulated semiconductor lasers is described. The drive circuit has a first circuit for generating a constant current and a second circuit for modulating the constant current. The second circuit generates, as a function of a digital data signal, a modulation current that is superimposed on the constant current, the modulated current being fed to a semiconductor laser. According to the invention, a third circuit is additionally provided which keeps the driver circuit at a low impedance during a rising edge and/or a falling edge of the current through the semiconductor laser. As a result, the signal shape of the optical output signals of the semiconductor laser can be improved, and the driver circuit can be operated at higher data rates, in particular at data rates of up to 12 Gbit/s.

Abstract: Parasitic oscillations are eliminated in solid-state laser components by applying a pattern of grooves to the peripheral sections that do not transmit the desired laser radiation. Additionally, the invention frustrates total internal reflections at polished peripheral component walls by providing a pattern of roughened surface sections in between polished sections. The roughened surfaces may be only microns deep or may be as deep as a few centimeters for large components. The grooves should be sufficiently deep as to inhibit any total internal reflections. The invention applies to all common solid-state architectures that are designed with polished surfaces that do not serve to propagate the desired laser radiation. Examples are slabs, plates, laser rods, waveguides and disks functioning as laser oscillators or amplifiers. The invention is operational with conventional crystal or glass laser hosts or with hosts that are composites of same, similar or dissimilar crystals or glasses.

Abstract: A near-field laser and detector apparatus and method wherein both writing and reading of optical media can be carried out using the same laser operating in a single mode for both read and write operations. The single operational mode can be utilized with both edge emitting and surface emitting laser configurations, and allows readout via rear facet output power variation or by voltage variation across the laser. A small aperture laser is operated during read and write operations at a bias current which is higher than the threshold currents associated with feedback from high and low reflectivity regions of an optical medium. The bias current and laser structure provide a relatively high, continuous output power from the front emission facet of the laser to facilitate writing, while providing substantial fluctuation or change in output power from the rear emission facet to facilitate readout.

Abstract: A real-time wavelength calibration scheme for a swept laser generates an electrical signal from a swept optical output of the swept laser that is cyclical with respect to the wavelength of the swept optical output over a defined range of wavelengths. The point on the electrical signal at any given time provides an accurate phase for the swept optical output at that point. The electrical signal in turn is calibrated by generating calibration references from the swept optical output using known absorption lines within the defined range of interest. The wavelength of the swept laser is calibrated as a function of a reference wavelength from the known absorption lines and the phase at the given point.

Abstract: The present invention provides a method and apparatus for controlling laser power, using at least two Brewster windows which are aligned along an axis which is parallel to the direction of the laser beam and which are rotatable around said axis, wherein the first Brewster window is rotated in one direction and the second Brewster window is rotated in the opposite direction. Preferably, both Brewster windows only have to rotate each through +/−45° to control transmission of the laser beam from maximum to minimum.

Abstract: A semiconductor laser array apparatus, comprising: a first laser array structure which includes a plurality of first laser oscillation units arranged side by side at an interval, and a first current blocking material filling a space between each pair of adjacent laser oscillation units and, a second laser array structure which includes a plurality of second laser array structure arranged side by side at an interval and a second current blocking material filling a space between each pair of adjacent second laser oscillation units. Here, laser beams from the activated first and second laser array structures leak to the outside of those laser array structure so as to form first and second distribution regions of the laser beams respectively, and the first and second laser array structures are close to each other so that the first and second distribution regions contact or overlap with each other.

Abstract: Optical amplifiers and other optical network equipment are provided for use in fiber-optic communications networks. The equipment may include dynamic spectral filters and optical channel monitors. Control units may be used to control the operation of the equipment. Components in the equipment may be interconnected using communications paths. The communications paths may include paths such as synchronous and asynchronous paths, point-to-point and multidrop paths, RS-232 paths, two-wire interface bus paths, parallel bus paths, and synchronous serial interface paths. The communications paths may be used to support an extensible equipment architecture that allows equipment features to be changed and added.

Abstract: Diamonds are marked by a laser beam having a characteristic that is changeable by positioning a selected aperture in the beam within a resonant cavity of a laser source. Guidelines are positioned in advance on the diamonds, and the marking is subsequently performed between the guidelines.

Abstract: A method and circuit is disclosed for providing a control signal to a laser cavity controller. The cavity has two completely reflective surfaces. A long lived laser medium stores energy within the cavity. A computer generated waveform generated from enough values to appear substantially smooth after being amplified is provided to a control circuit having a Pockels cell or a Bragg cell. By controlling the amplitude of the computer generated waveform, the output pulse of the laser cavity is controlled.

Abstract: A beam parameter monitoring unit is provided for use with a F2 laser system including means for filtering the red light from the VUV light of a beam portion split off from the mainbeam of the F2 laser before the beam portion reaches a detector. The filtering means includes a mirror that is highly reflective of VUV light (“VUV HR mirror”), particularly around 157 nm, and transparent to red light. The VUV HR mirror reflects the VUV light to a detector such that the properties and parameters of the main beam can be monitored, adjusted, controlled and/or stabilized. The VUV HR mirror is preferably surrounded by a shield for absorbing the red light transmitted through or around the VUV HR mirror. Also preferably, an aperture is provided that is just wide enough to permit the VUV radiation to substantially pass through, and to block the outer portions of the incident beam portion including substantially only red light.

Abstract: For each channel in a parallel channel optical array, a diffractive optical arrangement (DOA) includes an input region that is configured to pass a first portion of an input beam to an output region for data transmissions and to diffract and direct a second portion to a detection region for monitoring. The input region includes the diffractive features of a computer generated hologram (CGH) or a grating for diffracting. Alternatively, the input region is coupled to the CGH or grating. Moreover, the DOA includes at least one reflective region for redirecting the second portion. In one embodiment, the DOA includes a separate active surface for each channel of the array. Alternatively, the DOA has a singular active surface that is positioned to interact with all the channels. Optical power output from the second portion is monitored to generate feedback signals for adjusting the input current to each laser. Additionally, optical power output from sensed temperature is monitored to generate feedback signals.