Abstract: The object of the present invention is to provide an optical module for the WDM communication system, in which the oscillation wavelength is on the grid of the WDM regulation, moreover the optical output power and the oscillation wavelength can be controlled independently. The present module comprises a semiconductor light-emitting device, a wedge shaped etalon device and two light-receiving devices. The etalon device contains a first portion, on which the anti-reflection films are coated, and a second portion. One of the receiving devices detects light transmitted through the first portion of the etalon device, while the other device detects light through the second portion. Signal from the former device controls the output power of the light-emitting device, while the signal from the latter receiving device controls the oscillation wavelength of the laser.

Abstract: An optical margin testing system is provided for automatic power control loops. An optical circuit includes a laser diode and a monitor diode coupled to the automatic power control loop. A bias generator circuit generates a control signal. The control signal is applied to the automatic power control loop. The control signal enables an operation point of the laser diode to both increase and decrease by a set percentage value for optical margin testing. The bias generator circuit includes a tri-state receiver. An input signal is applied to the tri-state receiver for selecting one of a normal operational mode, an increased set percentage value operational mode, and a decreased set percentage value operational mode. A current mirror is coupled to the tri-state receiver provides the control signal that is applied to the automatic power control loop.

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

Abstract: The present invention relates to a laser apparatus comprising a laser light emitting optical system for emitting laser light to a surface, a power stabilizing system for stabilizing the laser light power with a predetermined power interval, and a deflection system for deflecting light reflected from the surface away from the power stabilizing system. Thereby, the power stabilizing system will not erroneously regulate the power due to reflections from the surface to be treated. Furthermore, the invention relates to a method for treating an animal, including a human being, for a laser light treatable disease using the laser apparatus on the skin or the mucosa of the animal and allowing laser light to be emitted from the laser light emitting optical system to the skin or mucosa.

Abstract: An optoelectronic device, such as a VCSEL, is disclosed whose transmission does not change upon encapsulation by a material such as plastic, epoxy or other suitable encapsulant with a known index of refraction. The surface reflection of the VCSEL surface is very different depending on whether it is terminated in air or the encapsulant, with a much larger reflection in the case of air. It is known that the surface reflection can be made out of phase with the rest of the mirror, effectively increasing the transmission. The amount of the transmission increase can be adjusted by controlling the thickness of the surface layer. Once the VCSEL is encapsulated, the surface reflection is reduced, and the transmission at the facet is increased but the dephased reflection is also reduced.

Abstract: The laser apparatus is disclosed that includes laser medium, a pair of mirrors and a regulator contained in the case, and is capable to regulate the output laser power without affection to the character of the laser light. A half-wave plate receives the laser light excited in the laser medium and rotates the plane of polarization of the laser light. A polarizer receives the laser light passed through the half-wave plate and separates the laser light into the first polarized straight light and the second polarized branch light. A photo detector detects the intensity of the second polarized light. According to the detected intensity, the half-wave plate is controlled to rotate to keep the intensity of the first polarized straight light constant. The laser apparatus also includes a maximum output display device to display the maximum output of the laser light and a final output display device to display the final output of the laser light.

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

Abstract: A method is disclosed for stabilization of the radiation output of a gas discharge-coupled radiation source in pulsed operation, particularly of an EUV source based on a gas discharge. The object of the disclosed invention is to find a novel possibility for stabilizing the radiation output of a gas discharge-coupled radiation source in pulsed operation which allows the pulse energy to be regulated on the basis of pulse energy fluctuations of the radiation emission detected through measurements without requiring regular calibration measurements of the E(U) curve in the stationary operating regime with continuous pulse sequences.

Abstract: The present invention provides a two VCSEL array mounted in a single can with a monitoring diode. One VCSEL is directed toward the can window (for coupling with an attached fiber optic in a completed subassembly) and the other is directed toward the monitor diode. The two VCSELS are electrically coupled in parallel, are connected to the same pins in the TO can, and are driven by the same source. Preferably the two VCSELS are identical or nearly identical. The current of the monitor diode is proportional to the light emitted by both VCSELs. Since the monitor diode measures incident light from the second VCSEL, no angle of reflection is affected by changes in temperature. Since the two VCSELs are coupled in parallel, the device has a naturally low impedance.

Abstract: A control circuit includes a power controller for adjusting a bias current to a laser diode to change the power output of the laser diode, the change in power having a corresponding wavelength shift effect on the nominal operating wavelength of the laser diode and a monitoring circuit for sensing the bias current to the laser diode and for generating an output signal in response to the sensed bias current. The control circuit further includes a wavelength controller which receives the output signal from the monitoring circuit and in response to the output signal compensates for the wavelength shift such that the laser diode maintains operation at the nominal wavelength.

Abstract: A lithography laser system for incorporating with a semiconductor processing system includes a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas, multiple electrodes within the discharge chamber and connected with a discharge circuit for energizing the laser gas, a resonator including the discharge chamber for generating a laser beam, and a processor. The processor runs an energy control algorithm and sends a signal to the discharge circuit based on said algorithm to apply electrical pulses to the electrodes so that the laser beam exiting the laser system has a specified first energy distribution over a group of pulses. The energy control algorithm is based upon a second energy distribution previously determined of a substantially same pattern of pulses as the group of pulses having the first energy distribution.

Abstract: A laser-diode-pumped solid-state laser apparatus includes a laser rod, and laser diode devices that generate pumping light. Optical unit such as a reflection mirror and an optical waveguide medium is provided at a position in a laser resonator near a laser optical axis and not blocking the optical axis. A photo-detector detects a quantity of fluorescence generated from solid-state laser medium. The fluorescence quantity is compared with a predetermined value or a previously measured value. Thus degradation status of a laser diode light source is constantly diagnosed.

Abstract: An arrangement for monitoring the emission wavelength of a laser source emitting a main radiation beam to be launched into an optical waveguide includes a wavelength selective photosensitive element adapted to be exposed to the radiation beam to generate an output signal indicative of the wavelength of the radiation. The arrangement comprises an optical system defining a beam propagation path for the radiation beam towards the waveguide. The wavelength selective photosensitive element is arranged at a marginal position of the beam, to collect at least a corresponding marginal portion of the radiation beam, whereby the signal indicative of the wavelength of the radiation is generated from said marginal portion of the radiation beam in the optical system.

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: 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: The invention relates to a method that can be used to compensate the influence of the temperature on the optical output power (light power) of light emitting diodes and laser diodes without the need to measure the temperature or light power. The method is based on the fact that the current flowing through a light emitting or laser diode and the forward voltage drop on the diode are at a constant light power independent of the temperature in a functional correlation that is often linear and can be obtained. If it is known, it must only be achieved during operation that the current and the forward voltage exhibit this correlation in order to eliminate the temperature effect on the light power.

Abstract: Provided are an apparatus for compensating for the characteristics of a laser diode and an optical transmitter including the apparatus. The apparatus includes: an optical output detector which detects an optical power output from the laser diode and converts the optical power into a voltage; a bias current controller which detects a maximum level of the voltage and outputs a first control value corresponding to a difference between the maximum level and a first reference voltage; a modulation current controller which detects a minimum level of the voltage and outputs a second control value corresponding to a difference between the minimum level and a second reference voltage; and a laser diode driver which outputs a drive current to the laser diode according to the first and second control values.

Abstract: A cavity length is determined on the basis of a relationship of electric drive power to a range of optical output power over 50 mW, for cavity length to be constant as a parameter in a range over 1000 &mgr;m, so that the electric drive power is vicinal to a minimum thereof in correspondence to a desirable optical output power. If the optical output is 360 mW for example, a cavity length of 1500 &mgr;m is determined to be selected.

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: An apparatus and method for modifying the spread of a laser beam. The apparatus comprises a laser source operable to generate a laser beam having a flux that exceeds a predetermined value and an optical train operable to modify the beam such that the flux of the beam through a predetermined aperture does not exceed the predetermined value. The optical train may include a focusing lens, a diffractive focusing vortex lens, a beam splitting device, or a two-dimensional diffraction grating.

Abstract: An optical transmitter having a packaging structure by which excellent optical transmitting waveform at high speed transmission is provided. An optical transmitter, comprising, a stem formed almost coaxial shape, a column fixed on said stem, a light emitting element chip provided on the column, terminals insulated with said stem and provided through the stem, and a connecting article connecting between the terminal and said light emitting element chip, wherein, the connecting article is formed by a line which is provided on an insulating substrate and is controlled to have predetermined characteristic impedance, and a resistive element for impedance matching connected to the line serially.

Abstract: Method to measure gain of a photonic inverter based on a semiconductor laser using two different modes of operation. In one mode, the device is operated as a photonic inverter device and in the other mode as a photogenerated current measurement device. While the device is operated in a photonic inverter mode, that is, pumped at a magnitude that supports photonic inverter operation, the optical output power is measured in the absence of an input signal and with an input signal that quenches the output of the photonic inverter. While the device is operated as a photogenerated current measurement device with an input optical signal, a reverse bias is applied to offset any forward bias induced by the injected input optical signal, the induced photocurrent is measured, and the wavelength of the input optical signal is measured.

Abstract: Methods and system are provided for automatic power control of a laser diode, e.g., in a laser driver. In accordance with an embodiment of the present invention, a power controller includes a detector circuit adapted to detect the output of the laser diode and to produce a measured output therefrom. A comparator compares a desired output to the measured output, and produces an error signal therefrom. The error signal is provided to an integrator circuit that produces an integrated error signal. At least one digital-to-analog converter (DAC) uses the integrated error signal to produce a current drive signal that drives the laser diode.

Abstract: A power controller is provided which can control the emission power from a light source to follow an appropriate response property based on a target value. The power controller includes feedforward systems for allowing currents corresponding to target values set at target value setting units to be switched at a switching device and supplied as a power setting current to an adder. Also included are feedback systems for detecting the power of the laser beam emitted by a semiconductor laser serving as the light source and adjusting a feedback current to stabilize the deviation from the target values at a predetermined value. Further included are a switching device for allowing the target values to be switched and supplied to the aforementioned feedback systems, and the adder for adding a feedback current and the power setting current to thereby generate a drive current for driving the semiconductor laser.

Abstract: A laser-based light source includes a laser (26), two optical detectors (27), a diffraction grating (29) mounted in a can (28), and a controlling circuit (31). A plurality of parallel grooves (293) is defined in a bottom face (292) of the diffraction grating. Each groove has a depth “d.” A groove separation “a” is defined between any two adjacent grooves. A groove cycle “b” is defined as a sum of the distance a and a width of any one groove. A light intensity of light beams depends on the values of “d”, “a” and “b”. By selecting a desired duty cycle f=a/b for the diffraction grating, the reflected light beams are converged into ±1 order light beams. Almost all the ±1 order light beams are collected by the optical detectors, notwithstanding variations in operational temperature. The controlling circuit receives feedback signals from the optical detectors.

Abstract: The present invention is for a ceramic calibration filter, in one embodiment a ceramic attenuator (410), for attenuating radiation between a light source (402) and a photodiode sensor (422). A laser signal is reduced by ceramic attenuator (410) to a low-level signal that can be measured the photodiode sensor (422). A focal plane (240) of the light source is offset from a face of the ceramic attenuator (410).

Abstract: Automatic power control (APC) is provided by a) a variable output voltage differential receiver/driver, which receiver is responsive to data signals for generating a voltage, the laser driver output voltage amplitude being controlled by a first potentiometer on an integrated circuit generating an AC current signal for summing with a DC current signal to provide a laser drive current signal to b) a laser transmitter having a laser diode, said laser diode for producing optical power over an optical transfer medium and a photodiode for producing a feedback signal in response to said optical power, the APC including c) a power stabilizing circuit including an error amplifier, a second potentiometer and a bias current drive transistor, the error amplifier having inputs for both the feedback signal and a voltage reference to generate an output control signal, the second potentiometer affecting said output control signal, and said bias current drive transistor being responsive to said output control signal for suppl

Abstract: A laser light intensity controller includes a polarizing beam splitter for passing most of one of an x-direction polarization component perpendicular to a direction in which a laser beam emitted from a light source travels and a y-direction polarization component parallel with the traveling direction and for reflecting a little portion of the one polarization component as monitoring light, and a photodetector for receiving the reflected monitoring light to generate a light intensity signal. The controller drives the light source in accordance with the light intensity signal. An optical element which passes passing only the one polarization component is installed between the light source and the polarizing beam splitter.

Abstract: A system and method for reducing peak power of a laser pulse and reducing speckle contrast of a single pulse comprises a plurality of beamsplitters, mirrors and delay elements oriented to split and delay a pulse or pulses transmitted from a light emitting device. The design provides the ability to readily divide the pulse into multiple pulses by delaying the components relative to one another. Reduction of speckle contrast entails using the same or similar components to the power reduction design, reoriented to orient received energy such that the angles between the optical paths are altered such that the split or divided light energy components strike the target at different angles or different positions. An alternate embodiment for reducing speckle contrast is disclosed wherein a single pulse is passed in an angular orientation through a grating to create a delayed portion of the pulse relative to the leading edge of the pulse.

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: An arrangement for monitoring the main radiation beam emitted by an optical source such as a laser diode (10) having a nominal emission wavelength, includes first (18) and second (20) photodetectors as well as a wavelength selective element (22). A beam splitter module (16) is provided for splitting a secondary beam from the main radiation beam of the laser source and directing it towards the first (18) photodetector via the associated wavelength selective element (22). The wavelength selective element (22) has a wavelength selective transmittance-reflectance characteristic, whereby said secondary beam is partly propagated towards said first (18) photodetector and partly reflected from said wavelength selective element (22) towards the second (20) photodetector. The output signals (18a, 20a) from the photodiodes (18, 20) have intensities whose behaviours as a function of wavelength are complementary to each other.

Abstract: Known devices for detecting wavelengths of received light require discrete components, which need to be placed with care and accurately aligned. Additionally, some known devices for detecting wavelengths have relatively large dimensions and do not lend themselves well to monolithic integration with other devices. The present invention provides a wavelength photodetector (100), for example, a p-i-n photodetector having a waveguide (110) disposed therein, the waveguide comprising a chirped Bragg grating (202) to provide wavelength selectivity. The waveguide photodetector (100) therefore generates a current linearly proportional to the wavelengths of light received. Advantageously, the waveguide photodetector can be integrally formed with other semiconductor devices and does not require precise alignment of discrete components.

Abstract: According to the present invention, an optical output automatic control circuit includes an optical output cutoff control circuit outside its feedback loop, and sets an optical output setting voltage at the ground level to prevent overshoot of the optical output while an optical output cutoff signal is being input.

Abstract: An apparatus, program product and method enable a host system to read a signal or signals that are proportional to the output power and/or the bias of a laser in a fiber optic link connected to that host system without breaking that link. By reading one or more of these signals and being aware of the laser characteristics, the “health” of the laser is known and the integrity of the link is maintained. Consequently, the host system has a predictive tool which is able identify substandard lasers and replace them before a serious, and potentially costly, data disruption occurs.

Abstract: A method and apparatus are provided to ensure that laser optical power does not exceed a “safe” level in an open loop parallel optical link in the event that a fiber optic ribbon cable is broken or otherwise severed. A duplex parallel optical link includes a transmitter and receiver pair and a fiber optic ribbon that includes a designated number of channels that cannot be split. The duplex transceiver includes a corresponding transmitter and receiver that are physically attached to each other and cannot be detached therefrom, so as to ensure safe, laser optical power in the event that the fiber optic ribbon cable is broken or severed. Safe optical power is ensured by redundant current and voltage safety checks.

Abstract: A method of wavelength locking and mode monitoring a tuneable laser that includes two or more tuneable sections in which injected current can be varied, including at least one reflector section and one phase section. Laser operation points are determined as different current combinations through the different laser sections, and the laser operates at a predetermined operation point. The wavelength of light emitted by the laser is detected by a wavelength selective filter. The laser is controlled in an iterative process in which alternated currents through the reflector section and, when applicable, its coupler section, and the current through the phase section are adjusted. The currents through the reflector section and the coupler section are adjusted to obtain a minimum ratio between power rearwards and power forwards. The current through the phase section is adjusted to hold the wavelength constant, the wavelength being measured against a wavelength reference.

Abstract: An intracavity frequency converted, Q-switched laser and method for operating such laser to obtain high output power in secondary pulses at a converted frequency. The secondary pulses are generated by a intracavity frequency conversion element from primary pulses at the fundamental wavelength. In accordance with the invention, after the primary and secondary pulses are generated the Q-switch is turned back on before the gain is fully depleted in the generation of the primary pulse. In particular, the Q-switch is turned back on such that a certain amount of energy of the primary pulse is retained in the laser, but late enough so that a majority of the secondary pulse is out-coupled from the laser. The Q-switched laser is well-suited for use at pulse repetition rates larger than 1/&tgr;, where &tgr; is an upper state lifetime (fluorescence lifetime) of the laser. Specifically, the laser can be operated at repetition rates of 10 kHz and higher, e.g.

Abstract: A pulse emitting laser is constantly controlled while recording data continuously to a desired power level without using test emissions or a high speed sample hold filter. The laser drive method detects beam emission power from a light source and generates a monitor wave; receives data and generates an expected wave for the beam power based on the received data; calculates the difference between the generated monitor wave and the expected wave; controls current flow from the bias current source based on the calculated waveform difference; and finally emits a beam from the light source based on the controlled current flow of the bias current source.

Abstract: A lithography laser system for incorporating with a semiconductor processing system includes a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas, multiple electrodes within the discharge chamber and connected with a discharge circuit for energizing the laser gas, a resonator including the discharge chamber for generating a laser beam, and a processor. The processor runs an energy control algorithm and sends a signal to the discharge circuit based on said algorithm to apply electrical pulses to the electrodes so that the laser beam exiting the laser system has a specified first energy distribution over a group of pulses. The energy control algorithm is based upon a second energy distribution previously determined of a substantially same pattern of pulses as the group of pulses having the first energy distribution.

Abstract: The invention relates to a device for generating a plurality of laser beams. The device comprises: a laser source emitting an initial beam at P wavelengths; a wavelength splitter assembly for splitting the initial beam into N intermediate beams where N≦P, each intermediate beam containing a group of wavelengths comprising at least one wavelength; and N′ energy splitter assemblies where N′≦N for splitting an intermediate beam into ni divisional beams, each of the ni divisional beams having substantially the same energy, whereby K divisional beams are obtained with K = N - N ′ + ∑ i = 1 i = N ′ ⁢ n i .

Abstract: The invention is directed to a method for the energy stabilization of a gas discharge-pumped radiation source that is operated in defined pulse sequences, particularly for suppression of overshooting and undershooting of excimer lasers and EUV radiation sources in burst operation. It is the object of the invention to find a novel possibility for the stabilization of the energy emission of a gas discharge-pumped radiation source that is operated in defined pulse sequences (bursts) which makes it possible to take into account a temporary behavior of the radiation source at the beginning of every burst without repeated recalibration of the energy-voltage curve.

Abstract: Laser printers are designed assuming the actual laser operates at nominal values which are the average or central values of a large batch of such lasers. The nominal values are determined and stored in permanent memory. Similarly, the values of the laser actually in the printer are determined during manufacture and also stored in permanent memory. Data to the laser is adjusted to correlate the output called for by the data with the differences in response of the laser of the printer by determining the optical output called for by the data using the nominal values stored and then finding the power needed to achieve the same output using the actual values stored. This is particularly useful with extreme duty cycles.

Abstract: An optical margin testing system is provided for automatic power control loops. An optical circuit includes a laser diode and a monitor diode coupled to the automatic power control loop. A bias generator circuit generates a control signal. The control signal is applied to the automatic power control loop. The control signal enables an operation point of the laser diode to both increase and decrease by a set percentage value for optical margin testing. The bias generator circuit includes a tri-state receiver. An input signal is applied to the tri-state receiver for selecting one of a normal operational mode, an increased set percentage value operational mode, and a decreased set percentage value operational mode. A current mirror is coupled to the tri-state receiver provides the control signal that is applied to the automatic power control loop.

Abstract: A wavelength-variable light source equipped with a semiconductor laser 1, one end of which is provided with an antireflection coating 1A, is equipped with a power correction filter 10 which permits transmission of the light output from the semiconductor laser 1, thereby rendering the characteristics of the output light substantially flat.

Abstract: An optical semiconductor module has a laser diode (LD) for emitting light, a first photo-diode (PD) and a second PD for receiving light emitted from the LD, and a wavelength filter which is disposed on a light path between the LD and the first PD and continuously changes the intensity according to wavelength of the light. The first PD generates an output current which is 20% or above larger than that of the second PD at the same intensity of the entered lights.

Abstract: The invention pertains to a control circuit (4) for a radiation source (2). The circuit comprises means (43) for generating an error signal (Perr) which is indicative for a difference between a measured average value of the output power of the radiation source (2) and a desired average value (Pset) of the output power of the radiation source. The circuit further comprises combining means (44, 45, 46) for generating a control signal (Sout) for the radiation source (2) in response to said error signal (Perr) and to an information signal (Sin) for modulating the radiation source. The combining means comprise first means (44) for modifying the information signal by a multiplicative factor &ggr; which is dependent on the error signal, and second means (45, 46) for modifying the information signal by an additive factor &sgr; which is dependent on the error signal.

Abstract: A molecular fluorine (F2) laser system includes a seed oscillator and power amplifier. The seed oscillator includes a laser tube including multiple electrodes therein which are connected to a discharge circuit. The laser tube is part of an optical resonator for generating a laser beam including a first line of multiple characteristic emission lines around 157 nm. The laser tube is filled with a gas mixture including molecular fluorine and a buffer gas. A low pressure seed radiation generating gas lamp is alternatively used. The gas mixture is at a pressure below that which results in the generation of a laser emission including the first line around 157 nm having a natural linewidth of less than 0.5 pm. The power amplifier amplifies the power of the beam emitted by the seed oscillator to a desired power for applications processing.

Abstract: A plastic encapsulated VCSEL and power monitoring system wherein the VCSEL and photodetector are encapsulated in an optoelectronic plastic molding material. A tilted window, with a partially reflective coating on one side, is attached to the top of the plastic molding material using an epoxy with a refractive index that substantially matches the molding material. The plastic encapsulated VCSEL and photodetector may be manufactured at low cost using standard molding techniques. The high optical quality of the tilted window and partially reflective coating provide an excellent surface to reflect a portion of the optical beam back to the photodetector. Also, the tilted window substantially reduces inconsistent power monitoring due to beam divergence and walk-off.

Abstract: For optical transmitters in DWDM network systems, a method of operating the semiconductor laser which provides the output of the optical transmitter. The output power and wavelength of the semiconductor laser is set by controlling the bias current and operating temperature according to a closed theoretical mathematical form. The form has the variables of output power, wavelength, bias current and temperature related to each other by empirically determined coefficients. In this manner the optical transmitter can efficiently vary its output power while maintaining its wavelength constant, or vary its wavelength while maintaining its output power constant.

Abstract: A variation in optical output of a semiconductor luminous device outputting an optical signal to an optical fiber which is caused due to a variation in ambient temperature and an end of a life thereof capable of being compensated for without measuring the optical output. An output variation quantity H0(Ta) of the semiconductor luminous device due to the ambient temperature Ta is operated in a step S2. In a step S4, an output reduction quantity ST of the semiconductor luminous device obtaining by accumulating an output reduction ST thereof per unit time due to a deterioration of the device is provided. In a step S5, it is judged that a life of the device reaches an end when the output reduction ST exceeds a reference value ST0. When the former fails to exceed the latter, a variation quantity IH(Ta) of a drive current command value due to the ambient temperature Ta and a current reduction quantity IST(ST, dST) determined due to a deterioration of the device are operated in a step S6.