Methods and systems for a polarization immune wavelength division multiplexing demultiplexer are disclosed and may include, in an optoelectronic transceiver having an input coupler, a demultiplexer, and an amplitude scrambler: receiving input optical signals of different polarization via the input coupler, communicating the input optical signals to the amplitude scrambler via waveguides, configuring the average optical power in each of the waveguides utilizing the amplitude scrambler, and demultiplexing the optical signals utilizing the demultiplexer. The amplitude scrambler may include phase modulators and a coupling section. The phase modulators may include sections of P-N junctions in the two waveguides. The demultiplexer may include a Mach-Zehnder Interferometer. The demultiplexed signals may be received utilizing photodetectors. The input coupler may include a polarization splitting grating coupler. The average optical power may be configured above which demultiplexer control circuitry is able to control the demultiplexer to process incoming optical signals.

The present disclosure relates to an apparatus for enhancing contrast sensitivity and resolution in a grating interferometer by machine learning, which can improve both image contrast sensitivity and spatial resolution in a grating interferometer by machine learning, the apparatus including: a grating interferometer image acquisition unit that acquires a relatively high resolution image and a relatively high sensitivity image by linearly moving the position of a sample from the symmetrical grating interferometer; a numerical phantom generation unit that generates a numerical phantom for performing machine learning; a convolution layer generation unit that performs calculation processing of a convolutional neural network to extract features from input data; an activation function application calculation unit that can apply a ReLu (Rectified linear unit) activation function to an output value of the convolution calculation to perform smooth repetitive machine learning; a CNN repetitive machine learning unit that corrects a convolution calculation factor while repeatedly performing forward propagation and backward propagation processes; and an image matching output unit that matches and outputs features extracted by repetitive machine learning of the CNN repetitive machine learning unit.

Embodiments described herein relate to waveguide combiners having arrangements for image uniformity. The waveguide combiners includes an input coupling grating (ICG) defined by a plurality of input structures, a pupil expansion grating (PEG) defined by a plurality of expansion structures, an output coupling grating (OCG) defined by a plurality of output structures The waveguide combiners includes at least one of a pixelated phase modulator is aligned with the PEG of the first side of the waveguide combiners, at least one of a Y expander and an X expander disposed on a second side of the waveguide combiners opposing the first side, or a pupil shifting mechanism operable to shift incident beams of light between a first position and a second position of the ICG.

An optical coupling device is presented. The optical coupling device comprises a plurality of input channels; a plurality of output channels; and a plurality of input coupling arrangements, or a plurality of output coupling arrangements, or a combination of both. Each input coupling arrangement has a coupling channel, and is configured to couple an optical signal propagating through a corresponding input channel into the coupling channel with an adjustable coupling coefficient. Each output coupling arrangement has a coupling channel and is configured to couple an optical signal propagating through the coupling channel into a corresponding output channel with an adjustable coupling coefficient.

A Mach-Zehnder Interferometer (MZI) includes a first arm having one or more first delay sections and respective first undercuts beneath the first delay sections, the first delay section(s) having a total first length and a first width. A second arm includes one or more second delay section(s) and respective second undercuts beneath the second delay section(s), the second delay section(s) having a total second length and a second width. The total first length is longer than the total second length, and the first width is less than the second width. The first width and the second width are selected to be less than a threshold width. For widths above the threshold width, variations in index-to-width tolerance are anticorrelated with respective variations in index-to-thickness tolerance and index-to-temperature tolerance. For widths below the threshold width, variations in index-to-width tolerance are correlated with respective variations in index-to-thickness tolerance and index-to-temperature tolerance.

Provided are a silicon-based tunable filter, laser and an optical module. The tunable laser comprises a semiconductor optical amplifier and a silicon photonic integrated chip, wherein a first coupler, a phase regulator and a tunable filter are provided on the silicon photonic integrated chip; the tunable filter comprises a flat-top band-pass filter structure, a Mach-Zehnder interferometry (MZI) structure and a micro ring resonation (MRR) structure, which are cascaded; gain light emitted by the semiconductor optical amplifier is coupled to the silicon photonic integrated chip by means of the first coupler, and a narrowband filtered optical signal is output by means of the tunable filter; and the phase of the gain light is regulated by means of the phase regulator so as to output single-peak narrowband laser light with a tunable target wavelength.