Abstract: Kerr and electro-optic frequency comb generation in integrated lithium niobate devices is provided. In various embodiments, a microring resonator comprising lithium niobate is disposed on a thermal oxide substrate. The microring resonator has inner and outer edges. Electrodes are positioned along the inner and outer edges of the microring resonator. The electrodes are adapted to modulate the refractive index of the microring. A pump laser is optically coupled to the microring resonator. The microring resonator is adapted to emit an electro-optical frequency comb when receiving a pump mode from the pump laser and when the electrodes are driven at a frequency equal to a free-spectral-range of the microring resonator.

Abstract: Kerr and electro-optic frequency comb generation in integrated lithium niobate devices is provided. In various embodiments, a microring resonator comprising lithium niobate is disposed on a thermal oxide substrate. The microring resonator has inner and outer edges. Electrodes are positioned along the inner and outer edges of the microring resonator. The electrodes are adapted to modulate the refractive index of the microring. A pump laser is optically coupled to the microring resonator. The microring resonator is adapted to emit an electro-optical frequency comb when receiving a pump mode from the pump laser and when the electrodes are driven at a frequency equal to a free-spectral-range of the microring resonator.

Abstract: Kerr and electro-optic frequency comb generation in integrated lithium niobate devices is provided. In various embodiments, a microring resonator comprising lithium niobate is disposed on a thermal oxide substrate. The microring resonator has inner and outer edges. Electrodes are positioned along the inner and outer edges of the microring resonator. The electrodes are adapted to modulate the refractive index of the microring. A pump laser is optically coupled to the microring resonator. The microring resonator is adapted to emit an electro-optical frequency comb when receiving a pump mode from the pump laser and when the electrodes are driven at a frequency equal to a free-spectral-range of the microring resonator.

Abstract: Disclosed are systems, methods, and structures for DSP-free coherent receiver architectures applicable for short-reach optical links. Operationally, a received optical signal is down-converted by mixing it with a local oscillator (LO) laser signal using a 90-degree hybrid followed by balanced photodiodes. Other receiver functions are performed using analog signal processing thereby avoiding power-hungry, high-speed analog-to-digital converters and high-speed digital signal processing. Carrier phase recovery is performed by an electrical phase-locked loop employing a multiplier-free phase estimator stage that—while designed for quaternary phase-shift keying signals—may be employed in designs exhibiting higher modulation formats. Since carrier phase recovery is performed in the electrical domain, LO laser frequency modulation or LO laser integration is not employed.

Abstract: Kerr and electro-optic frequency comb generation in integrated lithium niobate devices is provided. In various embodiments, a microring resonator comprising lithium niobate is disposed on a thermal oxide substrate. The microring resonator has inner and outer edges. Electrodes are positioned along the inner and outer edges of the microring resonator. The electrodes are adapted to modulate the refractive index of the microring. A pump laser is optically coupled to the microring resonator. The microring resonator is adapted to emit an electro-optical frequency comb when receiving a pump mode from the pump laser and when the electrodes are driven at a frequency equal to a free-spectral-range of the microring resonator.

Abstract: Disclosed are systems, methods, and structures for DSP-free coherent receiver architectures applicable for short-reach optical links. Operationally, a received optical signal is down-converted by mixing it with a local oscillator (LO) laser signal using a 90-degree hybrid followed by balanced photodiodes. Other receiver functions are performed using analog signal processing thereby avoiding power-hungry, high-speed analog-to-digital converters and high-speed digital signal processing. Carrier phase recovery is performed by an electrical phase-locked loop employing a multiplier-free phase estimator stage that—while designed for quaternary phase-shift keying signals—may be employed in designs exhibiting higher modulation formats. Since carrier phase recovery is performed in the electrical domain, LO laser frequency modulation or LO laser integration is not employed.

Abstract: A method for imaging a scan region by controlling at least one of the relative phase and relative amplitude of multiple optical modes propagating through a multimode optical fiber to control the position of an output beam emitted from the output facet of the optical fiber is disclosed.

Abstract: A method for imaging an object with resolution that exceeds the number of spatial modes per polarization in a multimode fiber is disclosed. In some embodiments, the object is interrogated with a plurality of non-spot-sized intensity patterns and the optical power reflected by the object is detected for each intensity pattern. The plurality of optical power values is then used in a non-local reconstruction based on an optimization approach to reconstruct an image of the object, where the image has resolution up to four times greater than provided by prior-art multimode fiber-based imaging methods.

Abstract: Optical signals are passed in an optical medium using an approach that facilitates the mitigation of interference. According to an example embodiment, a filtering-type approach is used with an optical signal conveyed in an optical fiber, such as a multimode fiber (MMF) or a multimode waveguide. Adaptive spatial domain signal processing, responsive to a feedback signal indicative of data conveyed in the multimode waveguide, is used to mitigate interference in optical signals conveyed in the multimode waveguide.

Abstract: Optical communications systems and methods transmit signals through an optical medium at a rate associated with a symbol interval. Receivers are communicatively coupled to the optical medium, and receive the signals. The received signals are processed using a plurality of filters. Each filter is used sequentially, one per symbol interval, during a sequence of consecutive symbol intervals. In certain exemplary embodiments, the tap spacing is K/M times the symbol interval, where K is the number of filters used, and M is an integer greater than K.

Abstract: Optical signals are passed in an optical medium using an approach that facilitates the mitigation of interference. According to an example embodiment, a filtering-type approach is used with an optical signal conveyed in an optical fiber, such as a multimode fiber (MMF) or a multimode waveguide. Adaptive spatial domain signal processing, responsive to a feedback signal indicative of data conveyed in the multimode waveguide, is used to mitigate interference in optical signals conveyed in the multimode waveguide.

Abstract: Optical signals are passed in an optical medium using an approach that facilitates the mitigation of interference. According to an example embodiment, a filtering-type approach is used with an optical signal conveyed in an optical fiber, such as a multimode fiber (MMF) or a multimode waveguide. Adaptive spatial domain signal processing, responsive to a feedback signal indicative of data conveyed in the multimode waveguide, is used to mitigate interference in optical signals conveyed in the multimode waveguide.

Abstract: Optical signals are passed in an optical medium using an approach that facilitates the mitigation of interference. According to an example embodiment, a filtering-type approach is used with an optical signal conveyed in an optical fiber, such as a multimode fiber (MMF) or a multimode waveguide. Modal dispersion in the optical signal is mitigated.

Abstract: A circuit using modular based parallel processing calculates the cumulative parity of a binary number input sequence. The circuit is used, for example, to implement a precoder for an optical duobinary transmission system. The design permits a relatively low-speed circuit to be used as the precoder before a time-division multiplexer. The parallel circuit can be scalable to process a very large number of sets of parallel binary data by the usage of two basic modules, namely, a parity module and a delay module.

Abstract: Optical data is processed and transmitted in a multimode transmission medium in a manner that facilitates the mitigation of interference such as that often referred to as intersymbol interference (ISI). According to an example embodiment of the present invention, a spatial light modulator is controlled to adaptively spatially filter light to be passed on a multimode transmission medium such as a multimode optical fiber.

Abstract: An optical homodyne receiver is realized by employing two separate signal amplification paths in a balanced receiver configuration. Specifically, the relative phase difference between a received optical signal and a local oscillator signal is extracted from nodes which, from the point of view of an amplifier extracting a data component signal, are at ac ground. This approach permits a phase detector amplifier, which extracts the relative phase component, to be dc coupled in addition to having a higher transimpedance for lower thermal noise, and thus higher sensitivity. Additionally, by extracting the data and phase component signals at different points in a balanced receiver configuration, the data and phase amplifiers can be separately engineered for optimum performance.