The invention describes an integrated photonics platform comprising a plurality of at least three vertically-stacked waveguides which enables light transfer from one waveguide of the photonic structure into another waveguide by means of controlled tunneling method. The light transfer involves at least three waveguides wherein light power flows from initial waveguide into the final waveguide while tunneling through the intermediate ones. As an exemplary realization of the controlled tunneling waveguide integration, the invention describes a photonic integrated structure consisting of laser guide as upper waveguide, passive guide as middle waveguide, and modulator guide as lower waveguides. Controlled tunneling is enabled by the overlapped lateral tapers formed on the same or different vertical waveguide levels. In the further embodiments, the controlled tunneling platform is modified to implement wavelength-(de)multiplexing, polarization-splitting and beam-splitting functions.

An intersecting splitter configured so that the branching ratio of each optical splitter differs in accordance with the difference in the number of intersections in each branched waveguide. The branching ratios (totaling 100%) of the optical splitters are adjusted so that the branching ratios on the high side as to the number of intersections is high in comparison with the branching ratios on the low side as to the number of intersections, and it is thereby possible to level the total loss.

An optical isolator for suppressing back reflections from a downstream optical system is described. The optical isolator includes a plurality of optical paths between a splitter and a combiner. One or more of the optical paths include two phase modulators that are driven by oscillating signals having predefined phase relationships. At least one bypass optical path does not include two phase modulators driven by oscillating signals. Amplitude and phase of an optical signal traversing the bypass optical path may be tuned to further suppress residual reflections from a downstream optical system.

A multi-mode interferometric optical waveguide device includes: a multi-mode interferometric optical waveguide which includes a first reflective surface; a first single-mode waveguide connected to the multi-mode interferometric optical waveguide; and a second single-mode waveguide connected to the multi-mode interferometric optical waveguide and oppose the first reflective surface. Consequently, the multi-mode interferometric optical waveguide device can propagate light from the first single-mode waveguide to the second single-mode waveguide, with further reduced optical losses.

A frequency-modulated continuous wave (FMCW) imaging light detection and ranging (LiDAR) system includes an integrated photonic circuit based coherent pixel array sensor having a large number of coherent pixels. Each pixel receives both the frequency-modulated signal light from a local light source (LO) and the returned signal light reflected from a section of the target scene through an imaging optical system. At each pixel, the LO light and the returned light are mixed locally by an optical mixer and then detected locally by an integrated photodetector. The electrical signal from each pixel is used to calculate scene distance using FMCW LiDAR principles. The LO signal is distributed into each pixel by an on-chip optical switch and routing circuit. An optical phased array may be used to split the source beam into the LO light and the target illumination light and to steer the illumination light.

A photonic integrated circuit comprises an input interface adapted for receiving an optical input signal and splitting it into two distinct polarization modes and furthermore adapted for rotating the polarization of one of the modes for providing the splitted signals in a common polarization mode. The PIC also comprises a combiner adapted for combining the first mode signal and the second mode signal into a combined signal and a decohering means adapted for transforming at least one of the first mode signal and the second mode signal such that the first mode signal and the second mode signal are received by the combiner in a mutually incoherent state. A processing component for receiving and processing said combined signal is also comprised.

An optical integrated circuit includes: a mode conversion and branching section that launches light from a first optical waveguide to a second optical waveguide, converts light from the first optical waveguide into converted light, and launches the converted light to a third optical waveguide; an optical multiplexing and branching section that multiplexes lights from the second and third optical waveguides into one multiplexed light component, and branches the multiplexed light component into a light component to be input to a fourth optical waveguide and a light component to be input to a fifth optical waveguide; a phase modulation section that is provided in at least one of the fourth and fifth optical waveguides and modulates a phase of guided light; and an optical multiplexing section that multiplexes light components from the fourth and fifth optical waveguides into one light component.

An apparatus comprising an optical filter located on a substrate. The optical filter including an optical splitter configured to receive an input light and an interferometer having two waveguide arms having different optical path-lengths from each other. The waveguide arms configured to receive the input light from the optical splitter. At least a portion of one of the two waveguide arms has a narrower core width than a wider core width of the other waveguide arm. The waveguide arm with the longest waveguide portion having the narrower core width has the longest total physical path-length of the two waveguide arms. At least one of the two waveguide arms having a set of discrete waveguide portions, the discrete waveguide portions of the set being connected by optical switches which are configured to tunably select from a plurality of different physical path-lengths through the discrete waveguide portions of the at least one waveguide arm.

Embodiments herein relate to photonic integrated circuits with an on-chip optical isolator. A photonic transmitter chip may include a laser and an on-chip isolator optically coupled with the laser that includes an optical waveguide having a section coupled with a magneto-optic liquid phase epitaxy grown garnet film. In some embodiments, a cladding may be coupled with the garnet film, the on-chip isolator may be arranged in a Mach-Zehnder interferometer configuration, the waveguide may include one or more polarization rotators, and/or the garnet film may be formed of a material from a rare-earth garnet family. Other embodiments may be described and/or claimed.

A switch module includes a switch integrated circuit (IC), an InP chip, and a planar lightwave circuit (PLC). The InP chip may include a plurality of light sources, an optical splitter, and a plurality of modulators.