A wavelength filter includes a first filter circuit and a second filter circuit. The first filter circuit that has a passband that is obtained from a vernier effect by connecting, in series, a plurality of ring resonators each having a different transmission wavelength interval and that is within a gain band of an optical amplifier, and that passes, from the gain band, light at a selected wavelength and light that has a wavelength in a recursive mode and that is produced on a short wavelength side or a long wavelength side of the selected wavelength. The second filter circuit is connected to the first filter circuit in series and suppresses the light at the wavelength in the recursive mode from the light passing through the first filter circuit.

An approach for realizing low-power, high-port-count optical switching systems, such as OXCs, WXCs, and ROADMs is presented. Optical switching systems in accordance with the present disclosure include arrangements of frequency-filter blocks, each of which includes a cascaded arrangement of tunable couplers and tunable Mach-Zehnder Interferometers (MZIs) that provides a substantially flat-top broadband transfer function for the frequency-filter block. The tunability for these devices is achieved by operatively coupling a low-power-dissipation phase controller, such as a stress-optic phase controller or liquid-crystal-based phase controller with one arm of the device, thereby enabling control over the coupling coefficient of the device.

Examples herein relate to optical systems. In particular, implementations herein relate to an optical system including an optical transmitter configured to transmit optical signals. The optical transmitter includes a first optical source coupled to an input waveguide and configured to emit light having different wavelengths through the input waveguide. The optical transmitter includes a Mach-Zehnder interferometer that includes a first arm and a second arm. The MZI further includes a first optical coupler configured to couple the emitted light from the input waveguide to the first and second arms and an array of two or more second optical sources coupled to the first arm. Each of the two or more second optical sources are configured to be injection locked to a different respective wavelength of the emitted light transmitted from the first optical source. The MZI further includes a second optical coupler configured to combine the emitted light from the first and second arms after propagating therethrough.

An optical computing device including a parametric oscillator array, an interaction computing matrix, a first feedback module connected to two ends of the parametric oscillator array, and a second feedback module connected to the parametric oscillator array and the interaction computing array. The parametric oscillator array is configured to receive a first group of signals, and generate a first group of optical signals including a plurality of first optical signals. The interaction computing array is configured to receive the first group of optical signals, and perform matrix operation on the first group of optical signals. The first feedback module is configured to receive the first group of optical signals, and transmit the first group of optical signals to the parametric oscillator array. The second feedback module is configured to receive the second group of optical signals, and transmit the second group of optical signals to the parametric oscillator array.

An optical modulator includes, a semiconductor substrate, an optical waveguide portion disposed on the semiconductor substrate, a first P-N junction disposed on the semiconductor substrate, and a second P-N disposed on the semiconductor substrate. The optical waveguide portion provides an optical path for light that is to be modulated. The first P-N junction is disposed on the semiconductor substrate along the optical path and defines a border between an N-doped portion disposed on the semiconductor substrate and a P-doped portion disposed on the semiconductor substrate. The second P-N junction is disposed on a portion of the semiconductor substrate alongside the optical path and spaced apart from the first P-N junction.

A manufacturing method for a photonic device includes dividing a target photonic network, which is a photonic network configured for the photonic semiconductor device, into a plurality of sub-photonic networks, forming the plurality of sub-photonic networks on a plurality of photonic chips, and connecting the plurality of sub-photonic networks on the plurality of photonic chips through a coupler to obtain the photonic semiconductor device carrying the target photonic network, wherein the coupler is configured to couple light from one photonic chip to another photonic chip. Compared with the scale of the photonic network of the existing photonic semiconductor device, which is limited due to the footprint limitation of a single chip, the scale of the photonic network of the photonic semiconductor device is increased several times.

Disclosed are a terahertz signal generation apparatus and a terahertz signal generation method using the same. The terahertz signal generation apparatus includes first and second resonators configured to respectively output an optical signal of a first resonant frequency and an optical signal of a second resonant frequency from an optical signal input through a gain medium, an optical modulator configured to optically modulate the output optical signal of the second resonant frequency, an optical combiner configured to combine the CW optical signal of the first resonant frequency and the modulated optical signal of the second resonant frequency, and a signal generator configured to generate a terahertz signal using heterodyne beating between the CW optical signal of the first resonant frequency and the modulated optical signal of the second resonant frequency, wherein the first resonant frequency and the second resonant frequency are processed to have a predetermined frequency difference.

A method and a system for arbitrary optical waveform generation from an optical input, the system comprising an optical shaper comprising unbalanced interferometers with at least one delay, the delay being selected of at least 0.1 ps, an optical sampling readout selected for measuring optical waveforms of at least 0.1 ps; and an electronic processing unit; wherein the optical input is a picosecond pulse; with a minimal pulse duration before the optical shaper equal to a minimal delay of the optical shaper; the optical shaper splitting and interfering optical pulses; the optical sampling readout collecting data at an output of the optical shaper; and the electronic processing unit comparing the collected data with a preset target and updating the optical shaper from results of the comparison until a maximal match between the output of the optical shaper and the preset target output, wherein the maximal match is determined iteratively using one of: machine-learning, optimization algorithms and iterative search algorithms.

A fiber optics polarization controller comprises: an optical fiber and multiple polarization stages. A first stage comprises: a motor having a hollow shaft spanning from a proximal end to a distal end along a rotational axis; and a fiber paddle affixed to and adapted to rotate with the hollow shaft. The fiber paddle has a ring-shaped body with two openings arranged opposite to each other around the ring-shaped body. A first opening of the fiber paddle is connected to the distal end of the hallow shaft substantially collinear with the rotational axis of the motor. The optical fiber is arranged spanning through the hollow shaft, entering the fiber paddle through the first opening, following around the ring-shaped body to form a fiber loop, and exiting the ring-shaped body through the second opening. A second stage is arranged in series with the first stage.

An electro-optic Mach-Zehnder modulator comprising a first and a second optical waveguide, and a plurality of pairs of electro-optic phase shifters forming segments, for each pair one phase shifter per optical waveguide, distributed over the length of the optical waveguides, wherein the electro-optic phase shifters are configured for phase-modulating the optical signals. The modulator, moreover, comprising at least one crossing element configured for crossing the optical waveguides between two segments.