Abstract: A driving circuit for a cathode-grounded type laser diode using NPN transistors is arranged to operate at high speed and to be less influenced by supply voltage fluctuations. A first NPN transistor is connected at a collector to a plus power source and at an emitter to the anode of the laser diode through a first resistor, and is supplied at a base with an externally given first control voltage. A second NPN transistor is connected at a collector to the anode of the laser diode and at an emitter to the ground through a second resistor. A logic buffer is provided for feeding a buffered output of an input data to the base of the second NPN transistor. The logic buffer is supplied as a supply voltage thereto with an externally given second control voltage.

Abstract: A linearized external modulator transmitter with improved dynamic range includes a limiter and a subtractor, which each receive one or more time-varying input signals. The limiter generates a first signal with an amplitude that is confined to a range bounded by preset positive and negative levels, wherein, between the preset levels, the transmitter has an optical power output that is linearly related to the input signal. The first signal is passed through a predistortion circuit connected to an external modulator as well as into the subtractor, which generates a signal equal to the amount by which the input signal exceeds, either positively or negatively, the limited first signal. The subtractor sends the excess signal to a tunable gain circuit connected to a laser. The laser is connected to the external modulator, which generates the optical power output of the transmitter. The transmitter can be adapted to include dual sets of inputs--e.g.

Abstract: The invented method and devices address signal regeneration and all-optical switching in optical fiber transmission lines. In modern optical networks, after several stages of optical amplification, the noise accumulation requires regeneration e.g. translation to electronic domain. A new type of optical repeater and optical switch are suggested to perform regeneration and switching on the optical level. The main component of the devices is an optical cavity implanted into a section of the optical fiber and bounded by fiber gratings. In the optical repeater, the fiber cavity is nonlinear; at resonant frequency, the cavity almost totally rejects the noise and transmits the signal. In the optical switch, the fiber cavity is linear; depending on the cavity tuning, the signal may be transmitted through the cavity or reflected and redirected to an appropriate switch port.

Abstract: A structure and method for packaging an integrated optic circuit. The package comprises a first wall having a plurality of microlenses formed therein to establish channels of optical communication with an integrated optic circuit within the package. A first registration pattern is provided on an inside surface of one of the walls of the package for alignment and attachment of the integrated optic circuit. The package in one embodiment may further comprise a fiber holder for aligning and attaching a plurality of optical fibers to the package and extending the channels of optical communication to the fibers outside the package. In another embodiment, a fiber holder may be used to hold the fibers and align the fibers to the package. The fiber holder may be detachably connected to the package.

Abstract: Free electron laser apparatus, for producing coherent electromagnetic radiation within a spectral range extending from millimeter to visible wavelengths, includes elements for generating an electron beam and for directing the beam to move over the surface of a diffraction grating, thereby producing electromagnetic radiation. Optical or quasi-optical elements confine the electromagnetic radiation, including bound surface mode radiation, to generate feedback, resulting in stimulated, coherent emission. Methods are disclosed for increasing the electron beam current above a certain value so as to provide sufficient feedback of the electromagnetic radiation for producing stimulated, coherent emission.

Abstract: An optical pulse generator comprises a resonant source of optical radiation, a modulator, and a source of modulating signals, wherein the modulator is operative to mode lock the resonant source and phase modulate the optical radiation in accordance with the modulating signals in such a manner as to produce dark pulses in the optical radiation.

Abstract: An optical wavelength stabilizing system including a laser diode for emitting signal light, a Peltier element for controlling a temperature of the laser diode, and a drive circuit for driving the Peltier element. The signal light is branched into two components by an optical coupler. In an optical path of one of the two components obtained by the optical coupler, there is inserted an optical filter having a portion whose transmittance continuously changes according to wavelength. The signal light component passed through the portion of the optical filter is detected by a photodetector. An output current from the photodetector is converted into a voltage, which is then input into a comparator. The comparator compares the voltage output from the photodetector and a reference voltage to input a voltage difference therebetween into the drive circuit.

Abstract: The invention provides a diode pumping module for a laser system, including a laser rod and a diode light source for excitation of the laser rod, the diode source being constituted by at least one diode array, a dual-function optical coupler/heat conductor located on one side of the laser rod between the at least one diode array and the laser rod, and attached to the rod, which coupler/heat conductor guides the light from the diode source into the rod while adjusting the angular spread of the light and also serves as heat conductor, conducting heat away from the rod. The system further includes a dual-function heat conductor/light reflector located on the opposite side of the laser rod, and attached to the rod, which conductor/reflector conducts the heat away from the laser rod and reflects unabsorbed diode light back into the rod.

Abstract: An autodyne lidar system utilizing a hybrid laser. The hybrid laser inclu a continuous wave (CW) optical gain section and a pulsed optical gain section in the same laser cavity. A highly reflecting mirror and a partially reflecting mirror, also called an output coupler, form the ends of a laser cavity. Both the continuous wave optical gain section and the pulsed gain section are positioned in the laser cavity. A detector is position in such a manner so as to observe the light reflecting through the cavity.

Abstract: A flat screen panel (1) comprising a base plate (9) and a plurality of optical fibers (2) laid in parallel on the base plate (9). Each of the optical fibers (2) has a modified portion (11) on its side (13) facing outwardly from the base plate (9), the modified portion (11) being able to transmit light therethrough. A plurality of light sources in arrays (4) are connected to the optical fibers (2) at one end thereof, each of the optical fiber (2) having at least one light source element (25) connected thereto. A drive circuit means is connected to the plurality of light sources to drive the light sources to transmit light through the optical fibers (2) and thence through the modified portions (11) of the optical fibers (2).

Abstract: The present invention is directed to methods and apparatuses for performing temporal scanning using ultra-short pulsewidth lasers in which only minimal (micro-scale) mechanical movement is required. The invention also relates to methods for obtaining high-accuracy timing calibration, on the order of femtoseconds. A dual laser system is disclosed in which the cavity of one or more of the lasers is dithered, by using a piezoelectric element. A Fabry-Perot etalon is used to generate a sequence of timing pulses used in conjunction with a laser beam produced by the laser having the dithered laser cavity. A correlator correlates a laser pulse from one of the lasers with the sequence of timing pulses to produce a calibrated time scale.

Abstract: An optical pulse source includes a gain-switched semiconductor laser diode (1). Light from a continuous wave source (3) is optically coupled into the laser cavity. Light output from the laser cavity passes through an electro-optic amplitude modulator (2). Synchronised modulating signals are applied to the semiconductor diode and to the amplitude modulator. The source outputs short low-jitter optical pulses and is suitable for use, for example, in a broadband optical network operating at high bit rates of 100 Gbit/s or more, or in an optical interconnect.

Abstract: An electrostatically controlled cantilever apparatus for continuous tuning of the resonance wavelength of a Fabry-Perot cavity is disclosed. A resonant cavity is formed between two distributed Bragg reflector (DBR) mirrors each composed of multiple DBR layers. One such layer is replaced with a layer which has been fully oxidized except for a small aperture. This layer provides both optical and current confinement which allows for low threshold currents and high output power.

Abstract: A laser apparatus for generating laser beams of predetermined wavelengths comprises a solid-state laser medium for generating a light beam having predetermined at least three fundamental wavelengths, at least three wavelength converters which respectively convert the light beam into harmonics corresponding to three primary colors of blue, green, and red, the wavelength-converter being circumferentially arranged, wavelength-converter holder for holding the wavelength converters, light blocking portions disposed between the wave length converters; rotating unit for rotating the wavelength-converter holder, thereby repeatedly positioning each of the wavelength converters and each of the light blocking portions on an optical axis of the solid-state laser medium, and a laser resonant optical system which resonates the light beams generated by the solid-state laser medium and outputs the harmonics converted by the wavelength converters.

Abstract: A current steering circuit accomplishes high speed switching of drive current through a vertical cavity surface emitting laser (VCSEL) diode. The preferred embodiment of the current steering circuit includes a first and second schottky diode, connected anode to anode, as the circuit elements used to steer the current that flows into the common connection point of the schottky diodes. The cathode of the first schottky diode is connected to the anode of the VCSEL diode. The cathode of the second schottky diode is connected to one side of a network formed from three resistors. The other side of the network is connected to the output of a CMOS invertor used to buffer the video signal which controls the steering of the current. With the output of the CMOS invertor at a high level, the second schottky diode is in the off state and the first schottky diode is in the on state, forcing drive current to flow through the VCSEL diode.

Abstract: A laser imaging apparatus comprising:a laser diode which is always operable in a linear lasing region;an amplitude modulator for amplitude modulating said laser diode for a digital image signal applied to said laser diode, when said digital image signal has a code value in a first range of code values in the mid to high range of signal code values; anda high speed pulse width modulator for pulse width modulating said laser diode when said digital signal, which is applied to said laser diode, has a code value in a second range of code values below said first range of code values, said laser diode being operated at a constant predetermined power level which is above the threshold power level of said laser diode.

Abstract: The invention relates to a method of fabricating an electro-optical device which comprises integrating a semiconductor component with a polymeric optical waveguide component. According to the invention, a semiconductor component obtained by epitaxial lift-off (ELO) is embedded in a waveguide device which in addition to a polymeric optical waveguide structure comprises an appropriate cavity. The invention further pertains to an integrated electro-optical device attainable by means of this ELO technique. Notably, it concerns an integrated electro-optical device in which the polymeric waveguide component and the semiconductor component are integrated on a substrate made of a different material from that of the semiconductor component, preferably a material with good heat dissipation, such as silicon. Preferably, the polymeric waveguide component comprises a polymer in which waveguide channels have been provided by bleaching.

Abstract: A frequency converting laser device includes a plurality of laser diodes each adapted to produce an output laser light beam and a plurality of optical fibers, each coupled to the output of a corresponding laser diode and including a built-in grating in the optical fiber arranged so as to provide a beam having a specific wavelength and to reflect a small portion of such beam back into the laser diode while transmitting the beam so that the laser diode will produce a beam of that wavelength. The device further includes frequency converting structure adapted to receive the transmitted beams of laser light and to change the frequency of each input beam to produce output beams at desired frequencies.

Abstract: A power boosted source of broadband optical power comprising a broadband light source, optical fiber amplifier and a relative intensity noise reduction system. The optical fiber amplifier amplifies the power level of the optical input signal to provide a power boosted source of broadband optical power out of an output port. A coupler samples a portion of the broadband optical power out of the output port as a sample portion signal. A detector and transimpedance amplifier detect the optical signal and provide a buffered signal having an instantaneous amplitude that faithfully characterizes the intensity of the sample portion signal. A bandpass amplifier amplifies the buffered signal and provides an output control signal to a light source responsive to a composite bias and control current for providing an output optical signal. The output optical signal is coupled to the input of the optical fiber amplifier to be the optical input signal to the optical fiber amplifier.

Abstract: A laser gun uses small arms technology for loading and firing a cartridge containing flash powder. When the cartridge is fired, the flash powder burns to produce an intense burst of light. This light is directed for optically pumping a laser medium that emits an intense pulse of laser light. The cartridge-based small arms technology allows the gun to be easily and conveniently carried about and fired rapidly and reliably.