Abstract: Structure and method for growing crystalline superlattice rare earth oxides, rare earth nitrides and rare earth phosphides and ternary rare-earth compounds are disclosed. The structure includes a superlattice having a plurality of layers that forming a plurality of repeating units. At least one the layers in the repeating unit is an active layer with at least one species of rare earth ion.

Abstract: Formation of a substantially flat upper cladding surface over a waveguide core facilitates transverse-coupling between assembled waveguides, and/or provides mechanical alignment and/or support. An embedding medium may be employed for securing optical assemblies and protecting optical surfaces thereof. Structural elements fabricated with a low-profile core may be employed for providing mechanical alignment and/or support, aiding in the encapsulation process, and so forth.

Abstract: A multi-layer laterally-confined dispersion-engineered optical waveguide may include one multi-layer reflector stack for guiding an optical mode along a surface thereof, or may include two multi-layer reflector stacks with a core therebetween for guiding an optical mode along the core. Dispersive properties of such multi-layer waveguides enable modal-index-matching between low-index optical fibers and/or waveguides and high-index integrated optical components and efficient transfer of optical signal power therebetween. Integrated optical devices incorporating such multi-layer waveguides may therefore exhibit low (<3 dB) insertion losses. Incorporation of an active layer (electro-optic, electro-absorptive, non-linear-optical) into such waveguides enables active control of optical loss and/or modal index with relatively low-voltage/low-intensity control signals. Integrated optical devices incorporating such waveguides may therefore exhibit relatively low drive signal requirements.

Abstract: An all-fiber Q-switched laser includes a gain fiber spliced between narrowband and broadband fiber gratings that define a polarization-dependent resonant cavity. The narrowband grating is, for example, formed in a PM fiber to create a polarization-dependent reflection band. A modulator applies stress to the fiber chain to induce birefringence and switch the cavity Q-factor to alternately store energy in the gain fiber and then release the energy in a laser pulse.

Abstract: A semiconductor optical amplifier (SOA) has an overall gain that is substantially polarization independent, i.e., less than 1 dB difference between transverse electric (TE) and transverse magnetic (TM) gain. The SOA includes gain and polarization rotation functions integrated onto a single substrate. According to one exemplary embodiment, a passive polarization rotation section is disposed between two active gain sections.

Abstract: An optical architecture is provided comprising at least one broadband light source, a mod/mux unit, and a plurality of premises stations in communication with the mod/mux unit via an optical distribution hub. The mod/mux unit is configured to permit selective modulation of demultiplexed components of a target wavelength band of an optical signal, multiplex the selectively modulated optical signal, and direct the target wavelength band and a bypass wavelength band of the multiplexed optical signal to the optical distribution hub. The optical distribution hub comprises an arrayed waveguide grating configured to demultiplex the multiplexed optical signal and distribute respective distinct wavelength portions of the target wavelength band and respective distinct wavelength portions of the bypass wavelength band to respective ones of the premises stations.

Abstract: Novel structures of the photodetector having broad spectral ranges detection capability (from UV to 1700 nm (and also 2500 nm)) are provided. The photodetector can offer high quantum efficiency >95% over wide spectral ranges, high frequency response >8.5 GHz. The photodiode array of N×N elements is also provided. The array can also offer wide spectral detection ranges (UV to 1700 nm/2500 nm) with high quantum efficiency >85% and high quantum efficiency of >8.5 GHz, cross-talk of <1%. In the array, each photodiode can be independently addressable. The photodetector element consists of the substrate, buffer layer, absorption layer, contact layer, and the illumination surface with thin contact layer. The illumination surface can be circular, square, rectangular or ellipsometrical in shape. The photodiode array consists of the photodiode elements of N×N, where each element can be independently addressable. The sensor can be fabricated as top-illuminated type or bottom-illuminated type.

Abstract: This invention discloses a “reflective arrayed waveguide grating,” (RAWG) for demultiplexing a multiplexed optical signal into its component wavelengths and for multiplexing n optical signals into a multiplexed signal. The present invention found that a single slab can be used for coupling the signal in and for focusing the signal out of the array of waveguide that functions as a grating; and a single external fiber array interface containing plurality of fibers can be used for both inputting the signal in and for outputting the signal from the RAWG. Advantageously, this method reduces the chip size and on-chip insertion loss by eliminating a slab and using 50% shorter waveguides in the array allowing significant savings of the silicon real estate. The smaller chip size increases the reliability of the device significantly and almost doubles the yield of chips per wafer.

Abstract: Illumination exposure control systems comprising reflective pixelated spatial light modulators that reflect substantially all of the light impinging on them into at least two different light paths. At least one of the light paths acts as a propagating light path and transmits the light beam out of the lighting system. At least one other light path acts as a non-propagating light path and prevents the light beam from being transmitted out the system. The illumination exposure control systems provide high speed of exposure actuation and precision control of exposure duration and frequency or exposure sequences.

Abstract: A device for collection of energy from mechanical disturbances and distribution of that energy to an electrical load. A transducer converts mechanical energy in the form of forces and displacements into electrical energy in the form of charge pulses. The charge pulses are rectified into a Direct Current (DC) power signal and accumulated and stored in an input storage element. A controlled conversion circuit assures that the voltage on the storage element is maintained within a predetermined optimal range for energy harvesting from the transducer, avoiding the application of peak voltages. The controlled conversion circuit can be hard wired and/or controllably adjustable to match a given disturbance characteristic. Only when the voltage is within the optimal range for a given type of disturbance will the controlled conversion circuit enable a DC/DC converter to further convert the stored energy to a voltage that is coupled to an output storage element.

Abstract: A resonant optical modulator comprises a transmission fiber-optic waveguide, a circumferential-mode optical resonator transverse-coupled thereto, a modulator optical component transverse-coupled to the circumferential-mode resonator, and a modulator control component. A control signal applied to the modulator optical component through the modulator control component alters the round-trip optical loss of the circumferential-mode resonator, thereby altering the transmission of a resonant optical signal through the transmission fiber-optic waveguide. The modulator optical element may comprise an open waveguide or a closed waveguide (i.e., resonator). The resonator round-trip optical loss may be altered by altering the optical absorption/scattering of the modulator optical component, by altering the amount of optical power transfer between the resonator and the modulator optical component, or by altering an optical resonance frequency of a resonant modulator optical component.

Abstract: A compact single frequency, single-mode 2 ?m fiber laser with narrow linewidth, <100 kHz and preferably <100 kHz, is formed with a low phonon energy glass doped with triply ionized rare-earth thulium and/or holmium oxide and fiber gratings formed in sections of passive silica fiber and fused thereto. Formation of the gratings in passive silica fiber both facilitates splicing to other optical components and reduces noise thus improving linewidth. An increased doping concentration of 0.5 to 15 wt. % for thulium, holmium or mixtures thereof produces adequate gain, hence output power levels for fiber lengths less than 5 cm and preferably less than 3 cm to enable single-frequency operation.

Abstract: A method for manufacturing a modular electrical circuit includes the steps of pre-manufacturing a plurality of components having fine features such as resistors, capacitors, inductances, and conductors formed on a dielectric substrate. The pre-manufactured components are laminated each to the other in a predetermined order. Each pre-manufactured component includes one or more electrical elements of the same type coupled each to the other by conducting lines. Each dielectric substrate includes through vias filled with the conductive material which serve for cross-coupling of the elements of neighboring components. Position of the passive elements, as well as conductive lines and through vias, are pre-designed to allow precise coordination between the elements of different components in the multi-layered modular electrical circuit.

Abstract: An optical architecture is provided comprising a plurality of mod/mux units, a master optical distribution hub, a plurality of additional optical distribution hubs, and a plurality of premise stations. Each of the mod/mux units is configured to (i) permit selective modulation of demultiplexed components of a target wavelength band of an optical signal, (ii) multiplex the selectively modulated optical signal, and (iii) direct the multiplexed signal to the master optical distribution hub. The master optical distribution hub is configured to distribute multiplexed signals from respective ones of the mod/mux units to corresponding ones of the plurality of additional optical distribution hubs. Each of the plurality of additional optical distribution hubs comprises an arrayed waveguide grating configured to demultiplex the multiplexed optical signal and distribute respective distinct wavelength portions of the target wavelength band to respective ones of the premise stations.

Abstract: A controller in an optical switch providing optical coupling of an optical signal between a source port and a target port employs, in at least one axis, gradient control using a feedback loop that compensates for alignment error between a source port and a target port in an optical switch. In at least one other axis, the controller generates a control input according to a control law that results in variable attenuation of optical coupling between the source port and the target port in the optical switch. A dither signal may be applied to the control input in the at least one other axis. Amplitude of the applied dither signal may be varied.

Abstract: The systems and methods described herein are directed to motion transformers as well as their integration and/or assembly, for use in directing optical beams and positioning of small optical elements for creating a variety of tunable optical components. More particularly, the systems and methods can be applied to a free-space optical cross-connect switching apparatus with piezoelectric actuation.

Abstract: A chiral in-fiber polarizer implemented in a chiral fiber structure having a core and a cladding surrounding the core, is provided. The chiral polarizer includes an entry end for receiving incident light and an exit end for outputting polarized light, as well as a pitch variation along its length between the entry and exit ends in accordance with a predetermined desirable pitch profile, wherein in one embodiment of the inventive polarizer, the inverse value of the chiral structure's pitch at the exit end is less than at the entry end, and preferably substantially equal to zero. The pitch profile may be advantageously selected to correspond to one or more predetermined pitch configurations, may be determined in accordance with one or more mathematical functions, or may be random.

Abstract: This invention provides a novel wavelength-separating-routing (WSR) apparatus that uses a diffraction grating to separate a multi-wavelength optical signal by wavelength into multiple spectral channels, which are then focused onto an array of corresponding channel micromirrors. The channel micromirrors are individually controllable and continuously pivotable to reflect the spectral channels into selected output ports. As such, the inventive WSR apparatus is capable of routing the spectral channels on a channel-by-channel basis and coupling any spectral channel into any one of the output ports. The WSR apparatus of the present invention may be further equipped with servo-control and spectral power-management capabilities, thereby maintaining the coupling efficiencies of the spectral channels into the output ports at desired values.

Abstract: This invention provides a novel wavelength-separating-routing (WSR) apparatus that uses a diffraction grating to separate a multi-wavelength optical signal by wavelength into multiple spectral characters, which are then focused onto an array of corresponding channel micromirrors. The channel micromirrors are individually controllable and continuously pivotable to reflect the spectral channels into selected output ports. As such, the inventive WSR apparatus is capable of routing the spectral channels on a channel-by-channel basis and coupling any spectral channel into any one of the output ports. The WSR apparatus of the present invention may be further equipped with servo-control and spectral power-management capabilities, thereby maintaining the coupling efficiencies of the spectral channels into the output ports at desired values.

Abstract: The invention provides a novel wavelength-separating-routing (WSR) apparatus that uses a diffraction grating to separate a multi-wavelength optical signal by wavelength into multiple spectral channels, which are then focused onto an array of corresponding channel micromirrors. The channel micromirrors are individually controllable and continuously pivotable to reflect the spectral channels into multiple output ports. As such, the inventive WSR apparatus is capable of routing the spectral channels on a channel-by-channel basis and coupling any spectral channel into any one of the output ports. The WSR apparatus of the present invention may be further equipped with servo-control and spectral power-management capabilities, thereby maintaining the coupling efficiencies of the spectral channels into the output ports at desired values.