Abstract: An apparatus and method for linewidth broadening applied to a laser that emits a light having an output frequency ? and an emission linewidth ?E. The apparatus is equipped with an electro-optic modulator for intercepting the light and a noise generator for driving the electro-optic modulator with a radio-frequency (RF) noise signal spanning a frequency range selected to broaden the emission linewidth ?E of the light passing through the electro-optic modulator to a broadened linewidth ?B. The noise spectrum of the noise signal exhibits a continuous frequency range and can be flat or sloping. The range extends from low frequency ?L set below the emission linewidth ?E of the light to a high frequency ?H set above the emission linewidth ?E of the light. The electro-optic modulator can be selected from among many suitable devices including optical crystals. Further broadening can be achieved by employing one or more secondary EOMs operating in resonant or non-resonant modes.

Abstract: An optical receiver may include a photodetector that is configured to generate an electrical signal in response to detecting an optical signal, a first gain path coupled to receive and amplify the electrical signal generated by the photodetector, and a second gain path coupled to receive and amplify the electrical signal generated by the photodetector. The second gain path may have a higher gain than the first gain path. The two gain paths may be configured to amplify the electrical signal independently of each other. The optical receiver may also include a switch that selectably outputs an amplified electrical signal from one of the gain paths based on a magnitude of a signal corresponding to the optical signal.

Abstract: An optical component mount with beam deviation monitoring and beam guiding system using such optical component mounts. The optical component mount has a location for mounting an optical element thereon for operating on the beam and at least one sensor attached to the optical mount at a predetermined position to at least one mode of the optical component mount. The predetermined position is selected depending on the state of the optical component mount. The state can be, e.g., a vibrational state or a thermal expansion state. The predetermined position is chosen near or at an anti-node of at least one mode contributing to the state. The state of the optical mount is determined based on the signals obtained from the at least one sensor, which can be an accelerometer in the case of monitoring a vibrational state or a temperature sensor in the case of monitoring a thermal expansion state.

Abstract: A tunable external cavity laser equipped with an optical path length compensator for adjusting an optical path length of the cavity, a wavelength selector for selecting an operating wavelength of the light in a single longitudinal mode and a dispersion compensator for compensating a dispersion of the light. In order to achieve mode-hop-free tuning the laser has a synchronizer for synchronizing the optical path length compensator, the wavelength selector and the dispersion compensator to maintain the light in the selected single longitudinal mode while the wavelength selector tunes the operating wavelength. The laser employs a pair of prisms and a wedge filter or a gap filter to perform the functions of the optical path length compensator, the wavelength selector and the dispersion compensator.

Abstract: A mover assembly (16) that moves or positions an object (12) includes a mover output (226), an actuator (230), and a measurement system (20). The mover output (226) is connected to the object (12), and the actuator (230) causes the mover output (226) to rotate about a first axis and move along the first axis. In this embodiment, the measurement system (20) directly measures the movement of the mover output (226) and provides feedback regarding the position of the mover output (226).

Abstract: A laser apparatus and method that provide for suppression of source spontaneous emission (SSE) and amplified spontaneous emission (ASE) light in laser output with minimal intracavity loss. The apparatus comprises a gain medium emitting a light beam, a wavelength element positioned in the light beam, and a non-reciprocal pickoff positioned in the light beam between the gain medium and wavelength element. The non-reciprocal pickoff may comprise a polarization-dependent beam splitter and a non-reciprocal polarization rotator positioned in the light beam before the wavelength selection element. The non-reciprocal pickoff may further comprise a reciprocal polarization rotator positioned in the light beam after the polarization-dependent beam splitter.

Abstract: A method and apparatus for controlling a piezo-electric actuator coupled to a driven member is disclosed. The piezo-electric actuator is responsive to waveforms with asymmetrical voltage/current profiles on the rising and falling edge to effect consistent and cumulative movement of the driven member in one of two directions throughout the reciprocations of the piezo-electric actuator. The waveforms are digitally generated from a stored set of numbers or a function for generating the set of numbers. The numbers correspond with the discrete digital values associated with the desired waveforms for moving the driven member in either of at least two directions. The controller may be used to drive more than one piezo-electric actuator. The controller may include responsiveness to a feedback of the position of the driven member to accurately position the driven member.

Abstract: The present invention provides a method and apparatus for packaging high frequency electrical and/or electro-optical components. The present invention provides a package which may be surface mounted on a board with other electrical components. The shielding provided by the package minimizes electromagnetic interference with other electrical components on the board. The package includes a controlled impedance I/O interface for coupling with the electrical and/or electro-optical component(s) in the package. The package interface may also include a differential I/O capability to further control electromagnetic fields generated at the interface. Additionally, the package may include an optical link provided by one or more optical fibers extending from the package.

Abstract: Apparatus and methods that provide a tunable laser output wavelength which varies linearly or with high predictability over time, and which can provide tuning speeds of greater than 100 nanometers per second. The apparatus includes a laser resonator cavity having first and second reflective elements, at least one of which is movable to provide a constant change in output wavelength with respect to time. A tuning assembly associated with the movable reflective element is structured, configured, and positioned to adjust the movable reflective elements such that constant changes in output wavelength and high tuning speeds are provided.

Abstract: The present invention provides an apparatus for mechanically stabilizing tunable lasers by mechanically grounding laser components. Lasers stabilized using mechanical grounding of the laser components exhibit phase synchronous tuning, reduced mode hop and increased wavelength stability across the entire tuning range. Additionally, lasers stabilized using mechanical grounding exhibit improved resistance to thermal and physical shock. The robust compact design of mechanically grounded lasers makes them suitable for a broad range of applications including optical signal generators and optical multimeters.

Abstract: A laser apparatus and method with compact cavity design that provides suppression of source spontaneous emission (SSE) and amplified spontaneous emission (ASE) light with minimal loss. The laser comprises a gain medium emitting a light beam along an optical path, a tuning element positioned in the optical path and configured feed back light of a selected wavelength to the gain medium and configured to define a first output beam directed along a first output path, a partial reflector located in the optical path and positioned to create a second output beam directed along a second output path substantially parallel to the first output path; and having a spontaneous emission component that is spatially separated from the selected wavelength. The second output beam can be coupled into optical fiber and produce a coherent light source with high spectral purity and tunable wavelengths.

Abstract: Disclosed is an external cavity diode laser system that includes a dispersion unit; a gain element producing coherent light incident upon the dispersion unit; and the dispersion unit dispersing the incident coherent light into dispersed light, the dispersed light comprising a reflected diffraction beam and at least one of angularly-separated source spontaneous emission or angularly-separated amplified spontaneous emission; a guiding dispersion unit that guides the dispersed light diffracted upon it from the dispersion unit while maintaining an angular separation between the reflected diffraction beam and at least one of angularly-separated source spontaneous emission or angularly-separated amplified spontaneous emission; and a physical filtering device that physically filters the reflected diffraction beam from the spatially separated at least one of angularly-separated source spontaneous emission or angularly-separated amplified spontaneous emission guided to the physical filtering device by the guiding unit

Abstract: The present invention provides a method and apparatus for transmission of optical communications. The present invention provides an optical transmitter which includes a control circuit to enhance the stability of output power levels, a modulator circuit with precise impedance matching for high frequency performance, and an optical coupling mechanism that relaxes the alignment tolerances between the laser and the fiber and decreases the sensitivity of the gain medium to feedback from devices coupled to the fiber. These features allow the transmitter to deliver an optical output beam which can be modulated over a wide range of frequencies, duty cycles and amplitudes with very precise definition of the rising and falling edges of the waveform. In combination these features result in an optical transmitter that may be fabricated with relatively low cost and a reduced form factor when compared with prior art optical transmitters.

Abstract: Disclosed is a microbend fiber optic coupler and a method of forming same. The microbend fiber optic coupler includes two pairs of pigtail ends oriented one beside the other and having a bent fused biconically tapered coupling region interposed therebetween.

Abstract: A system and method for real time process control, using a linearly swept tunable laser, which allows high speed in-situ monitoring and control of wavelength-specific properties of optical components. The invention comprises scanning an optical component with a high speed, high linearity tunable laser, and detecting optical output from the component during the scanning. Preferably, the invention also includes adjusting or controlling the optical properties of the component during scanning, according to detected optical output from the component. The invention is embodied in a process control system comprising a high speed, high linearity, tunable operatively coupled to an optical component which in turn is operatively coupled to an optical detector. A system control processor is operatively coupled to the tunable laser and detector. A processing control unit is associated with the optical component and is operatively coupled to the system control processor.

Abstract: A method and apparatus for minimizing the effects of noise when measuring a response of a device under test to laser light. Laser light provided from a laser source is provided to an interferometer, which splits the source laser light into a first laser light portion and a second laser light portion and then interferometrically combines the first laser light and the second laser light, resulting in a time-varying interference modulated test laser light and a time-varying interference modulated reference laser light. The time-varying interference modulated test laser light is propagated to a device under test so as to cause the device under test to propagate responsive time-varying interference modulated test laser light. The responsive time-varying interference modulated test laser light is converted to an responsive amplitude modulated electrical test signal, which is high pass filtered.

Abstract: The present invention provides a velocity matched distributed photodetector/modulator (VMDP) for converting between an optical signal and an electrical signal. The converter has twice the theoretical efficiency of any prior art device. The converter wave-guide core is of uniform cross-sectional thickness and composition along the optical path, which makes it easy to fabricate. The converter includes a passive optical waveguide and a plurality of photodiodes. The photodiodes optically couple in series with the passive optical waveguide and electrically couple in parallel with one another to convey the electrical signal there between. The photodiodes exhibit impedance mismatches that generate reflections of the electrical signal, which contribute to a cancellation of reverse traveling portions of the electrical signal.

Abstract: The present invention provides a continuously tunable external cavity laser (ECL) with a compact form factor and precise tuning to a selected center wavelength of a selected wavelength grid. The ECL may thus be utilized in telecom applications to generate the center wavelengths for any channel on the ITU or other optical grid. The ECL does not require a closed loop feedback. A novel tuning mechanism is disclosed which provides for electrical or mechanical tuning to a known position or electrical parameter, e.g., voltage, current or capacitance, with the required precision in the selected center wavelength arising as a result of a novel arrangement of a grid generator and a channel selector. The grid generator exhibits first pass bands which correspond to the spacing between individual channels of the selected wavelength grid and a finesse which suppresses side band modes of the laser. The channel selector exhibits second pass bands that are wider than the first pass bands.

Abstract: Described embodiments provide a method and apparatus for transmission of optical communications. An embodiment provides an optical transmitter which includes a control circuit to enhance the stability of output power levels, a modulator circuit with precise impedance matching for high frequency performance, and an optical coupling mechanism that relaxes the alignment tolerances between the laser and the fiber and decreases the sensitivity of the gain medium to feedback from devices coupled to the fiber. These features allow the transmitter to deliver an optical output beam which can be modulated over a wide range of frequencies, duty cycles and amplitudes with very precise definition of the rising and falling edges of the waveform. In combination these features result in an optical transmitter that may be fabricated with relatively low cost and a reduced form factor when compared with prior art optical transmitters.

Abstract: The present invention provides an apparatus for passively stabilizing the optical pathlength in tunable lasers. Lasers stabilized using the passive stabilization apparatus exhibit reduced mode hop and increased wavelength stability during temperature variations of the laser or surrounding environment. The stabilization makes the laser suitable for a broad range of applications including: optical signal generators and optical multimeters.