The optical phased array may use a grating based emitter in order to emit light out of the plane of a PIC chip from an array of output waveguides. A longer grating allows for a larger aperture in the output waveguide dimension and allows for a small spot size. However, even for the relatively thick grating layers available in production foundries, the gratings still cause light to decay within less than 0.5 mm. To reduce the grating strength, some or all of the diffraction gratings may only be provided between the output waveguides, e.g. over trenches between the output waveguides, but not over top the output waveguides, whereby the periodicity only interacts with the weaker evanescent tails of the confined mode instead of the entire cross section of the output waveguides. By forming sufficiently narrow slots in the grating layer only down to the upper cladding layer, the diffraction gratings may be made extremely weak.

An apparatus and method for temperature compensation, belonging to the technical field of optical communications, and particularly an apparatus and method for implementing bilinear temperature compensation of an arrayed waveguide grating is disclosed. The apparatus consists of two drivers. A first driver performs linear compensation in a range lower than normal temperature 25 C. to 40 C. (low-temperature area) or a range higher than ambient temperature 25 C. to 85 C. (high-temperature area). A second driver is used to realize nonlinear compensation of superimposed effect of AWG chip wavelength/temperature in another temperature area. Two parts of the chip after being divided have different relative displacement/effective compensation amounts in different temperature ranges, having over-compensation in the high-temperature area and under-compensation in the low-temperature area, so that a center wavelength of the AWG chip appears as two gentle curves with temperature change. The residual nonlinear temperature effect is effectively reduced.

An optical array waveguide grating-type multiplexer and demultiplexer according to an embodiment of the present invention comprise: a first substrate, a plurality of first waveguides disposed on the first substrate to be superposed in the vertical direction, which is the thickness direction of the first substrate; a 1-1st cladding layer disposed between the first substrate and a 1-1st waveguide, which is nearest to the first substrate among the plurality of first waveguides; a 1-2nd cladding layer disposed between the plurality of first waveguides; and a 1-3rd cladding layer disposed on a 1-2nd waveguide, which is furthest from the first substrate among the plurality of first waveguides.

A multi-path interference filter. The multi-path interference filter includes a first port waveguide, a second port waveguide, and an optical structure connecting the first port waveguide and the second port waveguide. The optical structure has a first optical path from the first port waveguide to the second port waveguide, and a second optical path, different from the first optical path, from the first port waveguide to the second port waveguide. The first optical path has a portion, having a first length, within hydrogenated amorphous silicon. The second optical path has a portion, having a second length, within crystalline silicon, and the second optical path has either no portion within hydrogenated amorphous silicon, or a portion, having a third length, within hydrogenated amorphous silicon, the third length being less than the first length.

The invention concerns an optoelectronic chip including a pair of optical inputs having a same bandwidth, and each being adapted to a different polarization, at least one photonic circuit to be tested, and an optical coupling device configured to couple the two inputs to the circuit to be tested.

An arrayed waveguide grating. The arrayed waveguide grating includes two star couplers and an array of waveguides connecting the star couplers. The T-shaped geometry of the array of waveguides makes possible an AWG with an arbitrarily large free spectral range in a compact form factor. An array mode converter produces a field pattern, at an aperture of a free propagation region of a star coupler, having overlapping modes from adjacent waveguides.

A two-dimensional optical phased array, including a first phased array and a second phased array disposed on the first phased array. The first phased array includes an optical coupler, a beam splitter, a plurality of phase shifters, and a plurality of light-emitting units. The second phased array includes a strip transparent electrode array, a phase shifting medium, and a transparent electrode disposed on the phase shifting medium. The strip transparent electrode array is disposed on the light-emitting units. The phase shifting medium is disposed on the strip transparent electrode array. The light-emitting units is configured to produce a laser beam which is incident to the second phased array via the strip transparent electrode array and emitted via the transparent electrode on the phase shifting medium.

The present disclosure is generally directed to an optical transceiver that includes a multi-channel on-board ROSA arrangement that includes an optical demultiplexer, e.g., an arrayed waveguide grating (AWG) and an array of photodiodes disposed on a same substrate. The array of photodiodes may be optically aligned with an output port of the optical demultiplexer and be configured to detect channel wavelengths and output a proportional electrical signal to an amplification circuit, e.g., a transimpedance amplifier. Each of the photodiodes can include an integrated lens configured to increase the alignment tolerance between the demultiplexer and the light sensitive region such that relatively imprecise bonding techniques, e.g., die bonding, may be utilized while still maintaining nominal optical power.

An arrayed waveguide for a photonic integrated circuit has a single optical path with serially connected delay lines. Different delayed optical paths or channels are periodically split off from the serially connected optical delay path. This has the net result of requiring much less space on-chip for comparable optical path differences with high spectral resolution.

Tapered cavity structures disposed within a stratum may be configured as a spectral component splitters, a spectral component combiners, and various combinations thereof including a reflective mode of operation. The tapered cavities have an aperture at their wider and a tip at the narrower, and are dimensioned such that multi-spectral radiant energy admitted into the cavity via the aperture would depart the tapered cavity via its side periphery at a depth and/or direction dependent on its frequency and/or its polarization, and that a plurality of spectral components admitted to the cavities via the its peripheral side or sides will be mixed and emitted via the aperture. Reflective type structures where portions of radiant energy is selectively absorbed and other portions are reflected are also considered. Differing stratums are disclosed. Applications of the tapered cavities in a stratum are also disclosed.