Abstract: A compact silicon waveguide mode converter, a dielectric meta-surface structure based on periodical oblique subwavelength perturbations, including a top silicon structure with oblique subwavelength perturbations etched in certain periods with period length of ?, a duty cycle and an oblique angle ? on the SOI substrate. The invention adopts an all-dielectric meta-surface structure with oblique subwavelength perturbation, which can achieve a compact mode conversion from fundamental mode to arbitrary high-order mode of silicon waveguide, and can improve the optical communication capacity greatly.

Abstract: A compact silicon waveguide mode converter, a dielectric meta-surface structure based on periodical oblique subwavelength perturbations, including a top silicon structure with oblique subwavelength perturbations etched in certain periods with period length of ?, a duty cycle and an oblique angle ? on the SOI substrate. The invention adopts an all-dielectric meta-surface structure with oblique subwavelength perturbation, which can achieve a compact mode conversion from fundamental mode to arbitrary high-order mode of silicon waveguide, and can improve the optical communication capacity greatly.

Abstract: The silicon waveguides consist of an input waveguide and an output waveguide, and the input and output silicon waveguides are arranged on the both sides of the Luneburg lens, respectively. The width of the input waveguide is larger than that of the output waveguide. The structure of the Luneburg lens is a metamaterial layer of the periodic silicon nanorod antenna array, which the upper cladding and the lower cladding are SiO2. The required refractive index distributions by the Luneburg lens can be implemented through the metamaterial structure of the gradient index profiles.

Abstract: The present invention discloses a photo-alignment apparatus that realizes a desirable distribution through a single exposure and a method of manufacturing an optical element. The photo-alignment apparatus comprises a light source, a linear polarization film, a pixelated electronic-control phase retarder, and a phase retardation plate; the light source is used to provide light for a exposure; the linear polarization film is configured to convert the light emitted by the light source into a linearly-polarized light having a polarization direction parallel to the direction of the transmission axis of the linear polarization film; the pixelated electronic-control phase retarder is configured to generate phase retardations distributed in a desirable pattern; and the phase retardation plate is used to generate a non-pixelated phase retardation.

Abstract: The present invention discloses a photo-alignment apparatus that realizes a desirable distribution through a single exposure and a method of manufacturing an optical element. The photo-alignment apparatus comprises a light source, a linear polarization film, a pixelated electronic-control phase retarder, and a phase retardation plate; the light source is used to provide light for a exposure; the linear polarization film is configured to convert the light emitted by the light source into a linearly-polarized light having a polarization direction parallel to the direction of the transmission axis of the linear polarization film; the pixelated electronic-control phase retarder is configured to generate phase retardations distributed in a desirable pattern; and the phase retardation plate is used to generate a non-pixelated phase retardation.

Abstract: An optical amplification method and apparatus implemented using RZ-DPSK modulation or variants thereof and a deeply saturated semiconductor optical amplifier.

Abstract: A method and system for ultra-high bit rate fiber-optic communications (e.g., 160 Gb/s) utilize a phase-correlated modulation format where phases of bits in adjacent four-bit groups in transmitted optical pulse trains are altered by ? (or 180°).

Abstract: A system and method for transmitting optically labeled packets using DPSK/ASK modulation. The system comprises a transmitter including at least two modulators adapted to provide DPSK modulation of a payload portion of optically labeled packets and ASK modulation for a label portion of the optically labeled packets. A receiver is also provided which includes a balanced detector for detection of the payload portion of the optically labeled packets.

Abstract: A method and system for ultra-high bit rate fiber-optic communications (e.g., 160 Gb/s) utilize a phase-correlated modulation format where phases of bits in adjacent four-bit groups in transmitted optical pulse trains are altered by ? (or 180°).

Abstract: A variable bandwidth hierarchical OADM apparatus and method handles different data rates, based on a waveband OADM and one or more wavelength OADMs in parallel. The wavelength OADM combines multiple adjacent channels with fine granularity up to the bandwidth of the waveband OADM. The wavebands and wavelengths to be passed, dropped, and added by the hierarchical OADM apparatus are all electronically selectable, hence no hardware modification is needed when the data rate is changed. The use of a coarse granularity waveband OADM and variable-bandwidth wavelength OADM with fine granularity enables our hierarchical OADM apparatus and method to provide a variable-bandwidth multi-granularity add/drop capability.

Abstract: A control circuit for a tunable laser has a logic circuit configured to generate a plurality of digital control signals using a table of calibration parameters stored in that circuit. The logic circuit receives an input signal specifying, e.g., an optical communication channel, retrieves the corresponding parameter values from the table of calibration parameters, and generates the digital control signals that are digital-to-analog converted, amplified, and applied to the tunable laser. The table of calibration parameters may be custom-generated for each particular tunable laser to accommodate laser-to-laser variations. In addition, the table of calibration parameters may be periodically updated to correct for wavelength drifting due to laser aging. A control circuit of the invention can be configured to update the table of calibration parameters in a non-disruptive continuous manner while the tunable laser controlled by the circuit is used for data transmission.

Abstract: An optical amplification method and apparatus implemented using RZ-DPSK modulation or variants thereof and a deeply saturated semiconductor optical amplifier.

Abstract: A system and method for transmitting optically labeled packets using DPSK/ASK modulation. The system comprises a transmitter including at least two modulators adapted to provide DPSK modulation of a payload portion of optically labeled packets and ASK modulation for a label portion of the optically labeled packets. A receiver is also provided which includes a balanced detector for detection of the payload portion of the optically labeled packets.

Abstract: A variable bandwidth hierarchical OADM apparatus and method handles different data rates, based on a waveband OADM and one or more wavelength OADMs in parallel. The wavelength OADM combines multiple adjacent channels with fine granularity up to the bandwidth of the waveband OADM. The wavebands and wavelengths to be passed, dropped, and added by the hierarchical OADM apparatus are all electronically selectable, hence no hardware modification is needed when the data rate is changed. The use of a coarse granularity waveband OADM and variable-bandwidth wavelength OADM with fine granularity enables our hierarchical OADM apparatus and method to provide a variable-bandwidth multi-granularity add/drop capability.

Abstract: A control circuit for a tunable laser has a logic circuit configured to generate a plurality of digital control signals using a table of calibration parameters stored in that circuit. The logic circuit receives an input signal specifying, e.g., an optical communication channel, retrieves the corresponding parameter values from the table of calibration parameters, and generates the digital control signals that are digital-to-analog converted, amplified, and applied to the tunable laser. The table of calibration parameters may be custom-generated for each particular tunable laser to accommodate laser-to-laser variations. In addition, the table of calibration parameters may be periodically updated to correct for wavelength drifting due to laser aging. A control circuit of the invention can be configured to update the table of calibration parameters in a non-disruptive continuous manner while the tunable laser controlled by the circuit is used for data transmission.

Abstract: A tunable fiber optic parametric oscillator includes a nonlinear optical loop mirror or fiber Sagnac interferometer NFSI with a dispersion shifted fiber portion. The oscillator is synchronously pumped to amplify a signal wave, while reflecting the depleted pump pulse back towards the pump. The amplified signal wave and simultaneously generated idler waves are directed to a spectral filter. The spectral filter may be a diffraction grating, a Faraday mirror or other optical filter that is tunable to change the signal wavelength that is reflected back to the NFSI. The fiber optic parametric oscillator is tunable over substantially the entire gain bandwidth and is insensitive to the polarization of the pump pulses. The fiber optic parametric oscillator may be used as a tunable source of short pulses for high speed optical communication systems. The fiber optic parametric oscillator may also be used for synchronization and clock recovery.