An optical module has an optical amplifier that amplifies an optical signal in which multiple wavelengths are multiplexed, an optical demultiplexer that separates the multiple wavelengths from the optical signal having been amplified by the optical amplifier, a first photodetector that monitors the optical signal at an input side of the optical amplifier, a second photodetector that monitors each of the multiple wavelengths at an output side of the optical demultiplexer, and a control circuit that controls a center wavelength of a filter of the optical demultiplexer based upon a first output from the first photodetector and a second output from the second photodetector.

An integrated circuit that includes an optical receiver is described. This integrated circuit may include an optical receiver. The optical receiver may include a photodiode that receives an optical signal and that outputs a corresponding current. Moreover, the optical receiver may include an inductor that is electrically coupled to the photodiode. Furthermore, the optical receiver may include a resistive analog front-end stage that is electrically coupled to the inductor. Note that the inductor may have a resistance per unit length that is greater than a first threshold value (such as 40 m/m), and the inductor may be approximately dispersion-less. For example, a Q factor for inductive peaking associated with the inductor is less than a second threshold value (such as 5).

A sparse optical phased array transmitter/receiver includes, in part, a multitude of transmitting/receiving elements that are sparsely positioned. Accordingly, the transmitting/receiving elements are not uniformly distributed at equal distance intervals along a one-dimensional, two-dimensional, or a three-dimensional array. The positions of the transmitting/receiving elements may or may not conform to an ordered pattern.

An optical receiver and a method of controlling the optical receiver. The method may include setting, by a controller, a dispersion value of a dispersion compensator to compensate for a dispersion of an optical signal received through an optical fiber, compensating, by the dispersion compensator, for the dispersion of the optical signal based on the set dispersion value, performing, by the controller, an error correction with respect to the optical signal of which the dispersion is compensated and verifying a number of bit errors, and resetting, by the controller, the dispersion value of the dispersion compensator based on the verified number of bit errors.

A free-space optical (FSO) communication system includes a transmitter including a modulated light source and transmit optics for emitting a modulated optical signal into a FS channel toward a receiver. A receiver is coupled to receive the modulated optical signal including receive optics coupled to a few-mode (FM) pre-amplifier that is coupled to a demodulator.

An integrated circuit that includes an optical receiver is described. This integrated circuit may include an optical receiver. The optical receiver may include a photodiode that receives an optical signal and that outputs a corresponding current. Moreover, the optical receiver may include an inductor that is electrically coupled to the photodiode. Furthermore, the optical receiver may include a resistive analog front-end stage that is electrically coupled to the inductor. Note that the inductor may have a resistance per unit length that is greater than a first threshold value (such as 40 m/m), and the inductor may be approximately dispersion-less. For example, a Q factor for inductive peaking associated with the inductor is less than a second threshold value (such as 5).

Optical telecommunications devices, systems, and methods. In some implementations, an optical networking unit (ONU) includes a multi-rate receiver having an operating bandwidth that is selected operationally based on physical layer characteristics of received signals and information received from a MAC. The ONU can also include an upstream laser circuit having an output impedance that differs from a characteristic impedance of a system in which the laser circuit is implemented. The ONU can also include a decision feedback equalizer (DFE) having at least one tap weight that is fixed to facilitate convergence of the DFE when signals received by the DFE would otherwise fail to meet characteristics required for DFE convergence.

A sparse optical phased array transmitter/receiver includes, in part, a multitude of transmitting/receiving elements that are sparsely positioned. Accordingly, the transmitting/receiving elements are not uniformly distributed at equal distance intervals along a one-dimensional, two-dimensional, or a three-dimensional array. The positions of the transmitting/receiving elements may or may not conform to an ordered pattern.

The invention relates to a wavelength division multiplexing optical receiver that is provided with a polarization splitting grating coupler and a driving method for the same, where the power consumption is reduced, and at the same time, a degradation in the receiver sensitivity is suppressed. Two monitor photodetectors configured to monitor the light intensity of a first polarization component and a second polarization component separated by a polarization splitting optical coupler are provided, and a control circuit is provided in order to allow a semiconductor optical amplifier that amplifies the first polarization component and another semiconductor optical amplifier that amplifies the second polarization component in accordance with the signal intensity ratio of the two monitor photodetectors to amplify light with different light gains.

Optical telecommunications devices, systems, and methods. In some implementations, an optical networking unit (ONU) includes a multi-rate receiver having an operating bandwidth that is selected operationally based on physical layer characteristics of received signals and information received from a MAC. The ONU can also include an upstream laser circuit having an output impedance that differs from a characteristic impedance of a system in which the laser circuit is implemented. The ONU can also include a decision feedback equalizer (DFE) having at least one tap weight that is fixed to facilitate convergence of the DFE when signals received by the DFE would otherwise fail to meet characteristics required for DFE convergence.