H04B10/69

Polarization-diversity Kramers-Kronig heterodyne receiver and method

An apparatus includes an input receiving a modulated optical data signal having components of at least first and second polarizations, a first optical detector receiving the data signal, the first optical detector being first polarization-selective or first polarization-sensitive, passing components of the data signal having the second polarization, and outputting a first electrical signal, a second optical detector coupled to the first optical detector to receive the components of the data signal having the second polarization, and outputting a second electrical signal, and a processor applying a Kramers-Kronig process to the first and second electrical signals, and outputting the data signal using the Kramers-Kronig processed first and second electrical signals. A combiner is connected between the input and the first optical detector and combines the data signal with an unmodulated optical signal such that the unmodulated optical signal serves as a Kramers-Kronig carrier for the first and second polarizations.

Multi-axis MEMS mirror parking
11693187 · 2023-07-04 · ·

The present disclosure provides an improved method of parking a microelectromechanical system (MEMS) mirror in an array of MEMS mirrors to protect against single high voltage channel failures in a driver. Two separate voltages are applied to each MEMS mirror to move and park the mirror out of a camera sensor field of view in a servo system. For example, a first voltage may be applied in a positive X direction and a second voltage may be applied in a positive Y direction which will move the mirror in a diagonal direction. If one of the high voltage channels fail, the mirror will still be parked and outside of the camera sensor field of view. If a high voltage channel fails, the servo system can park a mirror affected by the failure in an opposite corner. Moreover, if 2-axis parking is not feasible, the mirror can use single-voltage parking.

Multi-axis MEMS mirror parking
11693187 · 2023-07-04 · ·

The present disclosure provides an improved method of parking a microelectromechanical system (MEMS) mirror in an array of MEMS mirrors to protect against single high voltage channel failures in a driver. Two separate voltages are applied to each MEMS mirror to move and park the mirror out of a camera sensor field of view in a servo system. For example, a first voltage may be applied in a positive X direction and a second voltage may be applied in a positive Y direction which will move the mirror in a diagonal direction. If one of the high voltage channels fail, the mirror will still be parked and outside of the camera sensor field of view. If a high voltage channel fails, the servo system can park a mirror affected by the failure in an opposite corner. Moreover, if 2-axis parking is not feasible, the mirror can use single-voltage parking.

Light intensity signal transmitting device based on high-speed LED array

Disclosed is a light intensity signal transmitting device based on a high-speed LED array. The light intensity signal transmitting device includes an LED array and a control board card; through a novel arrangement and driving mode, the LED array has a high-speed modulation characteristic and can transmit high-bit light intensity information at the switching speed of single-point LEDs; the control board card performs high-speed display by gating an I/O port of the LED array, and is used as a light intensity signal transmitting end to transmit a light signal. According to the light intensity signal transmitting device, on the premise that the switching rate of the LED array is ensured, multi-bit binary data transmission is realized, and the transmission rate is improved.

Light intensity signal transmitting device based on high-speed LED array

Disclosed is a light intensity signal transmitting device based on a high-speed LED array. The light intensity signal transmitting device includes an LED array and a control board card; through a novel arrangement and driving mode, the LED array has a high-speed modulation characteristic and can transmit high-bit light intensity information at the switching speed of single-point LEDs; the control board card performs high-speed display by gating an I/O port of the LED array, and is used as a light intensity signal transmitting end to transmit a light signal. According to the light intensity signal transmitting device, on the premise that the switching rate of the LED array is ensured, multi-bit binary data transmission is realized, and the transmission rate is improved.

MULTI-ELEMENT LASER-BASED FULL-DUPLEX FREE-SPACE OPTICAL TRANSCEIVER
20230006742 · 2023-01-05 ·

A free-space optical (FSO) transceiver having an optimum number of transmitters and receivers positioned in optimum locations on the transceiver plane to ensure maximum signal-to-interference and noise ratio (SINR) and to minimize the effects of vibration of the mobile platform and atmospheric turbulence. A defocal lens assembly having an adjustable distance between the transmitters and the lens assembly is further provided to maximize the optical coupling efficiency and the vibration tolerance by adjusting the defocusing length.

Subcarrier based adaptive equalization of electrical filtering effects on sub-carrier multiplexed signals
11539447 · 2022-12-27 · ·

Consistent with the present disclosure, the above-described subcarrier noise, which may be characterized as a linear filtering effect, may be reduced or eliminated by providing a first multiple-input multiple output (MIMO) circuits at the transmit end of an optical link and providing a second MIMO circuit at the receive end of the optical link. The first MIMO may include a first plurality of filters, each of which may include a finite-impulse response (FIR) filter having variable coefficients or tap weights that may be changed or adapted to minimize subcarrier noise associated with the modulator, as well as D/A and analog circuitry, at the transmit end of the optical link. In addition, the second MIMO may include a second plurality of filters, each of which may also include an FIR filter having variable coefficients or tap weights that may be changed or adapted to minimized subcarrier noise associated with the optical hybrids, as well as A/D and analog circuitry, at the receive end of the optical link. In one example, a least means square (LMS) technique may be employed to calculate desired coefficients or tap weights whereby an error determined based on the signal detected at the receiver is minimized to update the coefficients of the FIR filters.

Optical receiver

Disclosed is an optical receiver. The optical receiver includes a circuit board, a base member, a photodetector mounted on the base member, a transimpedance amplifier, and a capacitor. The base member is disposed between a first grounding pattern and a second grounding pattern on a first side of the circuit board. The transimpedance amplifier is mounted on the first grounding pattern. The capacitor is mounted on the second grounding pattern. The first wiring pattern and the second wiring pattern are apart from both the first grounding pattern and the second grounding pattern in a plan view of the first side. The first grounding pattern is electrically connected to the second grounding pattern through a grounding pattern formed on the first side.

OPTICAL CHANNEL PLAN PROCESS

Methods for configuring an optical link in which a distribution of transmission data rates and line rates are configured for a predetermined amount of optical bandwidth to maximize transmission capacity. In these methods, a controller of an optical network obtains input parameters that include a signal-to-noise ratio (SNR) for optical signals and an allocated bandwidth of the optical link, further obtains, for each line rate, a mapping of transmission data rates along a frequency spectrum of the allocated bandwidth compatible with the SNR, and generates a channel plan in which a number of traffic modes and a distribution of a plurality of channels in the allocated bandwidth are set to maximize transmission capacity. The plurality of channels is used for transmitting the signals on the optical link. The controller configures at least one optical network element in the optical network to establish the optical link based on the channel plan.

Signal processing apparatus and optical receiver

An ADC (12) in an optical receiver (1) generates a sample signal composed of time series samples by oversampling a received signal that is an electrical signal converted from an optical signal by a light receiving unit (11). A symbol timing detection unit (132) of a DSP unit (13) detects a symbol timing in the sample signal. When it is determined that a symbol timing is appearing at a longer interval than a predetermined interval based on this detection result, a symbol timing adjusting unit (133) skips one or more samples included in the sample signal to read out samples at the predetermined interval, while when it is determined that the symbol timing is appearing at a shorter interval than the predetermined interval, the symbol timing adjusting unit inserts the same samples as one or more samples included in the sample signal immediately after the one or more samples to read out the samples at the predetermined interval.