Abstract: A predistorter for an electro-optical converter includes a plurality of low noise RF amplifiers distributed along a transmission line that receive an RF input. Second order intermodulation injection (IM2) circuitry includes an inductively-degenerated frequency doubler to square and filter IM2 products of the RF input. A Mach-Zehnder Modulator (MZM) is used for electro-optical conversion. Feed forward circuitry injects IM2 to independently propagate RF intermodulation components with velocity matching to the MZM. At least one driver injects the RF input and RF intermodulation components into the MZM.

Abstract: A predistorter for an electro-optical converter includes a plurality of low noise RF amplifiers distributed along a transmission line that receive an RF input. Second order intermodulation injection (IM2) circuitry includes an inductively-degenerated frequency doubler to square and filter IM2 products of the RF input. A Mach-Zehnder Modulator (MZM) is used for electro-optical conversion. Feed forward circuitry injects IM2 to independently propagate RF intermodulation components with velocity matching to the MZM. At least one driver injects the RF input and RF intermodulation components into the MZM.

Abstract: A fiber-optic gyroscope is disclosed, wherein the fiber-optic gyroscope has counter-propagating light signals in a closed-loop optical path, and where the light signals are characterized by an orthogonality that mitigates optical coupling between them. In some embodiments, the orthogonality is a difference in frequency of the two signals. In some embodiments, the orthogonality is a difference in the polarizations of the two signals. The orthogonality is imparted on the light signals by a non-reciprocal element that is optically coupled with the optical path. In some embodiments, a gain-balancing filter is also included to ensure that the loop gain for each light signal is substantially equal to one. In some embodiments, the light signals are provided by a gain element that is characterized by inhomogeneous broadening.

Abstract: A fiber-optic gyroscope is disclosed, wherein the fiber-optic gyroscope has counter-propagating light signals in a closed-loop optical path, and where the light signals are characterized by an orthogonality that mitigates optical coupling between them. In some embodiments, the orthogonality is a difference in frequency of the two signals. In some embodiments, the orthogonality is a difference in the polarizations of the two signals. The orthogonality is imparted on the light signals by a non-reciprocal element that is optically coupled with the optical path. In some embodiments, a gain-balancing filter is also included to ensure that the loop gain for each light signal is substantially equal to one. In some embodiments, the light signals are provided by a gain element that is characterized by inhomogeneous broadening.

Abstract: An apparatus is described to provide multi-channel bulk optical power detection. The apparatus has a plurality of optical splitters coupled to respective fiber-optic lines of a plurality of fiber-optic lines. An optimal time-division multiplexer has an input coupled to the plurality of optical splitters. A photodetector is coupled to an output of the optical time-division multiplexer to provide bulk optical power detection. The optical time-division multiplexer includes a scanning mirror.

Abstract: An apparatus is described to provide multi-channel bulk optical power detection. The apparatus has a plurality of optical splitters coupled to respective fiber-optic lines of a plurality of fiber-optic lines. An optimal time-division multiplexer has an input coupled to the plurality of optical splitters. A photodetector is coupled to an output of the optical time-division multiplexer to provide bulk optical power detection. The optical time-division multiplexer includes a scanning mirror.

Abstract: A filter apparatus is described that includes an electrical input signal, an optical source, an optical modulator, first and second pluralities of photonic delay lines, an optical switch, a combiner, and a photodetector. The optical modulator is coupled to the electrical input signal and the optical source. The first plurality of photonic delay lines are coupled to the optical modulator. The optical switch is coupled to the optical switch. The combiner combines the outputs of the second plurality of photonic delay lines to provide a combined output. The photodetector is coupled to the combined output of the combiner to provide a first filtered output of the electrical input signal.

Abstract: An optical switch for routing arbitrary wavelengths between optical fibers in optical networks. The optical switch may include a highly wavelength dispersive element together with a spatially dispersive element to separate the wavelengths. Broadband switch inputs and outputs may be provided for adding and dropping arbitrary wavelengths at each node of the network. Fiber demultiplexers and multiplexers may also be used to reduce the impact of mirror array yield on switch functionality.

Abstract: A method for equalizing optical signal power in a group of optical signals transmitted through an optical switch in an optical transmission system. In one embodiment a group of optical signals is input into an optical switch having at least one movable mirror array with a plurality of reflectors formed thereon, the optical beam being directed onto a selected at least one reflector and wherein attenuating the optical beam is accomplished by controllably detuning at least one of the selected at least one reflector to attenuate the optical beam.

Abstract: An apparatus and method of controlling optical loss in an optical switch to equalize optical power or loss in a group of optical signals in an optical transmission system relatively insensitive to mechanical vibration. In one embodiment a group of optical signals is input into an optical switch and selected optical signals are variably attenuated using synchronized control to two mirrors in order to provide more uniform power distribution among the group of optical signals without enhancing vibration sensitivity of the optical switch.

Abstract: An apparatus and method of controlling optical loss in an optical switch to equalize optical power or loss in a group of optical signals in an optical transmission system relatively insensitive to mechanical vibration. In one embodiment a group of optical signals is input into an optical switch and selected optical signals are variably attenuated using synchronized control to two mirrors in order to provide more uniform power distribution among the group of optical signals without enhancing vibration sensitivity of the optical switch.

Abstract: A method for equalizing optical signal power in a group of optical signals transmitted through an optical switch in an optical transmission system. In one embodiment a group of optical signals is input into an optical switch having at least one movable mirror array with a plurality of reflectors formed thereon, the optical beam being directed onto a selected at least one reflector and wherein attenuating the optical beam is accomplished by controllably detuning at least one of the selected at least one reflector to attenuate the optical beam.

Abstract: An apparatus and method of controlling optical loss in an optical switch to equalize optical power or loss in a group of optical signals in an optical transmission system relatively insensitive to mechanical vibration. In one embodiment a group of optical signals is input into an optical switch and selected optical signals are variably attenuated using synchronized control to two mirrors in order to provide more uniform power distribution among the group of optical signals without enhancing vibration sensitivity of the optical switch.

Abstract: An apparatus and method of controlling optical loss in an optical switch to equalize optical power or loss in a group of optical signals in an optical transmission system relatively insensitive to mechanical vibration. In one embodiment a group of optical signals is input into an optical switch and selected optical signals are variably attenuated using synchronized control to two mirrors in order to provide more uniform power distribution among the group of optical signals without enhancing vibration sensitivity of the optical switch.

Abstract: An optical cross-connect with integrated optical signal tap is disclosed. In one embodiment, the switch includes two or more optical fiber input ports, lenses to produce collimated beams, one or more optical taps to couple a portion of the optical power from one or more input ports to one or more sample ports, movable mirrors to connect any input port with any output port, two or more optical fiber output ports, and lens to couple collimated beams into the output ports.

Abstract: An optical switch having switch mirror arrays controlled by scanning beams that reduce the amount of electrical connections required and reduce the complexity for constructing large optical switches. Movement of the switch mirror arrays is controlled by one or more scanning beams. The optical switch includes one or more arrays of optical switch inputs and outputs and one or more arrays of movable mirrors to direct light beams from the optical switch inputs to the optical switch outputs. The optical switch also includes one or more control elements to control the movable mirrors based on scanning beams directed to the one or more control elements.

Abstract: An external modulation optical communication system suppressing the intensity noise of a semiconductor laser source by making substantially different optical path lengths for the optical paths in the interferometric modulator. Noise reduction is dependent on the correlation between intensity noise and frequency noise of the semiconductor laser. The interferometer path delay difference forms an optical filter that transforms frequency fluctuations into intensity fluctuations that are out of phase with the laser intensity fluctuations. The intensity modulation induced by frequency noise can be out of phase with the optical source intensity fluctuations, leading to total intensity noise at the output of the optical link which is lower than the laser intensity noise. Because the optical interferometer is already present for optical modulation, the optical filter realized by the unequal path delays of the interferometer does not add optical loss.

Abstract: An apparatus comprising an optical fiber array, a spacer to receive a light beam from the optical fiber array, and a lens array having an input to receive the light beam from the spacer and an output to output the light beam is disclosed. The spacer has a first refraction index and the lens has a second refraction index.

Abstract: An apparatus for digitizing an analog electrical signal comprises a linearized sampler having an analog electrical input and a sampling input, a bandpass filter having a center frequency of at least half of the quantization rate of a quantizer in communication with the sampler, and the quantizer in communication with the bandpass filter. The linearized sampler in one embodiment is a linearized optical modulator with an optical input. The sampler frequency in another embodiment is chosen such that second-order distortion products generated in the sampler are separated in frequency from the sampled input band.

Abstract: A technique and system of intensity noise suppression is disclosed using delayed differential noise cancellation, which can be applied to external modulation links. This technique is particularly suited to external modulation links using semiconductor diode laser sources, but is not limited to this type of laser. Laser sources also can be followed with an optical amplifier to increase the optical power, which also adds intensity noise. In this noise cancellation method, the intensity noise can be generated by the laser or the optical amplifier, or a combination of both. A bandpass differential method is disclosed which cancels optical intensity noise like the conventional differential method but operates only over a narrow RF bandwidth. Here the two complementary output signals of the modulator are subtracted by delaying one output by half of the modulation period (180° or an odd multiple thereof) and then summing the optical signals.