Abstract: An example embodiment includes a system for communicating an optical signal. The system includes an optical transmitter and an optical receiver. The optical transmitter includes one or more lasers configured to produce a light signal and a transmitter optical sub assembly (TOSA) receptacle. The TOSA receptacle optically couples the lasers to an optical fiber and launches a quasi-multimode optical signal (quasi-MM signal) that includes at least one lower order mode optical signal and at least one higher order mode optical signal onto the optical fiber. The optical receiver is connected to the optical fiber via a receiver optical sub assembly (ROSA) receptacle. The optical receiver is configured to receive the quasi-MM signal and to substantially block the at least one higher order mode optical signal.

Abstract: Systems and methods for gravity independent gripping and drilling are described. The gripping device can also comprise a drill or sampling devices for drilling and/or sampling in microgravity environments, or on vertical or inverted surfaces in environments where gravity is present. A robotic system can be connected with the gripping and drilling devices via an ankle interface adapted to distribute the forces realized from the robotic system.

Abstract: An example embodiment includes a system for communicating an optical signal. The system includes an optical transmitter and an optical receiver. The optical transmitter includes one or more lasers configured to produce a light signal and a transmitter optical sub assembly (TOSA) receptacle. The TOSA receptacle optically couples the lasers to an optical fiber and launches a quasi-multimode optical signal (quasi-MM signal) that includes at least one lower order mode optical signal and at least one higher order mode optical signal onto the optical fiber. The optical receiver is connected to the optical fiber via a receiver optical sub assembly (ROSA) receptacle. The optical receiver is configured to receive the quasi-MM signal and to substantially block the at least one higher order mode optical signal.

Abstract: The invention discloses phase-shifters, modulators, and method that produces a smaller ? by means of a field excitation using multiple electrodes. A negative signal is introduced that travels with the positive signal, which enhances the electric field significantly. The field enhancement is provided by the superposition of the fields accumulated from each electrode. A base or substrate material can be made from any compound having linear electro-optic properties, such as lithium niobate, lithium tantalite, potassium lithium niobate, potassium titanyl phosphate or gallium-arsenide. For lithium niobate, there are two possible orientations of electric field, z-cut orientation or x-cut orientation.

Abstract: The system includes a receiver for receiving a bit stream; an error monitor for indicating a first error rate for a first set of data received in the bit stream; and an adjustable circuit for converting an incoming signal into the bit stream using a reference signal that is modulated using a control signal. The system also includes a subsystem for correlating the first error rate and the control signal to generate the reference signal. The control signal has an amplitude that is selected so that a second set of data received in the bit stream has a second error rate that is less than the first error rate.

Abstract: An apparatus for reshaping optical pulses divides an incoming optical signal (10) into a first (14) and a second (16) path. The signal in the second path (16) is converted into an electrical signal which provides information concerning the pulse power of individual pulses. An optical modulator (22) is provided in the first, purely optical path (14) for modifying the optical signal so as to attenuate the pulses by an amount which depends on the power of the pulses, higher power pulses being attenuated more than lower power pulses. This helps maintain a constant signal to noise ratio within the system and can extend the number of optical spans of an optical signal before it requires full electrical regeneration.

Abstract: The invention discloses phase-shifters, modulators, and method that produces a smaller &pgr; by means of a field excitation using multiple electrodes. A negative signal is introduced that travels with the positive signal, which enhances the electric field significantly. The field enhancement is provided by the superposition of the fields accumulated from each electrode. A base or substrate material can be made from any compound having linear electro-optic properties, such as lithium niobate, lithium tantalite, potassium lithium niobate, potassium titanyl phosphate or gallium-arsenide. For lithium niobate, there are two possible orientations of electric field, z-cut orientation or x-cut orientation.

Abstract: The invention discloses phase-shifters, modulators, and method that produces a smaller &pgr; by means of a field excitation using multiple electrodes. A negative signal is introduced that travels with the positive signal, which enhances the electric field significantly. The field enhancement is provided by the superposition of the fields accumulated from each electrode. A base or substrate material can be made from any compound having linear so electro-optic properties, such as lithium niobate, lithium tantalite, potassium lithium niobate, potassium titanyl phosphate or gallium-arsenide. For lithium niobate, there are two possible orientations of electric field, z-cut orientation or x-cut orientation.

Abstract: An intermediate optical amplifier stage of an optical amplifier having cascaded amplifier stages includes an optical circulator having a first port forwardly coupled with a second port which is forwardly coupled with a third port, wherein the second port is optically coupled with an orthogonal polarisation state converting reflector via a length of optically pumped optically amplifying optical fibre. The orthogonal polarisation state converting reflector may be constituted by the series combination of a collimating lens, a Faraday rotator that provides a &pgr;/4 plane of polarisation rotation in respect of a single transit of light through the rotator, and a mirror.

Abstract: In a WDM optical transmission system employing optical amplifiers in its transmission path, a supervisory signal channel, used for monitoring and controlling the operation of the amplifiers and spectrally separated from the data transmission, may be multiplexed with the data. A construction of amplifier is disclosed which is capable of being upgraded with an upgrade of the transmission system to include additional data handling capacity, for instance data transmission in an additional waveband and/or in the opposite direction, without interruption of the pre-upgrade data transmission path through the amplifiers. This is accomplished by the use of channel dropping and insertion filters disposed so that the amplifying data transmission path extends via the drop/insertion channel of those filters.

Abstract: An optical amplifier for use in a WDM transmission system has a circulator two of whose ports constitute the input and output ports of the amplifier, and to whose third port is connected an optically amplifying fibre. Bragg grating reflectors are formed at specific intervals along this fibre chosen such that each WDM channel is reflected back to the circulator at a distance in inverse proportion to the gain per unit length experienced by that channel in the amplifier fibre, whereby all channels are amplified by the amplifier to the same extent.

Abstract: A self homodyne direct detection optical transmission system includes a transmitter in which binary data signals are converted into double differential phase shift keyed (DDPSK) optical signals. The receiver includes a two-path optical interferometer, having a path unbalance optical delay substantially equal to 1 bit period, to which received DDPSK signals are applied. The interferometer output is converted into a plurality of balanced phase diversity outputs. From each of the phase diversity outputs a replica of the binary data signals is recovered and the replica signals are combined to form an output binary data signal.

Abstract: A polarization state insensitive optical discriminator is provided by a Mach Zehnder interferometer (21, 22, 23, 24) constructed in polarization preserving optical fibre, and two optical fibre polarization beam splitters (20, 25). Each polarization beam splitter is interconnected with the interferometer in such a way that its two orthogonally polarized outputs are launched to opposite ends of the interferometer with the same state of polarization.