Disclosed is a compact on-chip polarization splitter-rotator based on a Bezier curve gradient waveguide. The Bezier curve gradient waveguide structure is a standard SOI-based wafer structure, comprising a substrate, of which the bottom layer is buried with oxide (SiO.sub.2), and the top is composed of silicon waveguides, including a common output waveguide and a specially-structured waveguide containing Bessel curve boundaries. The common waveguide structure is composed of a cuboid waveguide, and the specially-structured waveguide is composed of an input region, an output region, a width-gradient waveguide (Bezier curve gradient structure) and a coupling region, where a width of the gradient waveguide is determined by a third-order Bezier curve, and the coupling region is composed of two asymmetrical waveguide regions.

An apparatus includes multiple dual cladding waveguides each having a single-mode interior section that transports one of multiple outgoing optical signals and a multimode section at least partially surrounding the interior section that transports one of multiple incoming optical signals. Different outgoing signals have different polarizations, and different incoming signals have different polarizations. The apparatus also includes a polarization beamsplitter that combines the multiple outgoing signals to produce transmit optical signals and separates receive optical signals to produce the multiple incoming signals.

A system includes an optical transceiver configured to transmit and receive optical signals. The optical transceiver includes a Faraday rotator and a waveplate. The Faraday rotator and the waveplate are collectively configured to provide a relative polarization change between (i) light propagating in a first direction through the Faraday rotator and the waveplate and (ii) light propagating in a second direction opposite the first direction through the Faraday rotator and the waveplate. The waveplate may include a quarter waveplate or a half waveplate.

An optical input polarization management device includes a polarization splitter and rotator (PSR) that directs a portion of incoming light having a first polarization through a first optical waveguide (OW). The PSR rotates a portion of the incoming light having a second polarization to the first polarization so as to provide polarization-rotated light. The PSR directs the polarization-rotated light through a second OW. Light within the first and second OW's is input to a first two-by-two optical splitter (2×2OS). A first phase shifter (PS) is interfaced with either the first or second OW. Light is output from the first 2×2OS into a third OW and a fourth OW. Light within the third and fourth OW's is input to a second 2×2OS. A second PS is interfaced with either the third or fourth OW. Light is output from the second 2×2OS into a fifth OW for further processing.

A polarization rotator structure includes: a first core structure formed at a first layer, extending from the first end to a second end, and a second core structure formed at a second layer that is at a different depth than the first layer and formed in proximity to the first core structure. The first core structure and the second core structure provide mode hybridization between at least two orthogonally polarized waveguide modes of the PRS. An optical splitter structure is optically coupled at a first end to the second end of the PRS, and optically coupled at a second end to at least two optical waveguides, and includes: a first core structure that is contiguous with at least one of the first or second core structures of the PRS, and a second core structure that is separate from both of the first and second core structures of the PRS.

The invention concerns a polarization rotator. The inventive polarization rotator comprises an optical coupler comprising a waveguide having at one first end at least a first port configured as an input port for polarized light and a second port configured as an output port for reflected polarized light, said waveguide having a second end opposite to said first end. It further comprises a birefringent waveplate having on one side a reflective surface, which waveplate is arranged to receive light from said second end of said waveguide and to reflect light transmitted out from said coupler back into said coupler. According to the invention, the waveplate is further configured to cause said birefringent material to rotate the polarization of said reflected light, which amount of rotation depends on an angle of rotation of said birefringent waveplate with respect to said optical coupler.

The invention concerns a polarization rotator, comprising a first waveguide layer containing at least a first waveguide, said first waveguide having an input end and an output end, a second waveguide layer having at least a second waveguide, said second waveguide having an input end and an output end, and at least a first vertical mirror element arranged at the end of at least one of said waveguides to couple light between the output end of the first waveguide and the input end of the second waveguide. The optical axis of said first or second waveguide which has the vertical mirror element at its end is rotated in its waveguide layer at a first angle in order to induce rotation of polarization of light coupled between said first and second waveguides with an amount that corresponds to said first angle.

A polarization rotator structure includes: a first core structure formed at a first layer, extending from the first end to a second end, and a second core structure formed at a second layer that is at a different depth than the first layer and formed in proximity to the first core structure. The first core structure and the second core structure provide mode hybridization between at least two orthogonally polarized waveguide modes of the PRS. An optical splitter structure is optically coupled at a first end to the second end of the PRS, and optically coupled at a second end to at least two optical waveguides, and includes: a first core structure that is contiguous with at least one of the first or second core structures of the PRS, and a second core structure that is separate from both of the first and second core structures of the PRS.

Methods for design and production of highly sensitive active and passive light detecting devices and systems. Orders of magnitude improvement in optical signal detection is made possible in high noise or low contrast scenes. The current invention creates a small spectral difference between two parts of a split light stream. When recombined, the altered light streams partially correlate, and that generates fall amplitude signal oscillation at a frequency that depends on the constituent spectrum. The full amplitude signals and spectrum dependent oscillation make signal discrimination much better than intensity-only methods. The effect of read noise, amplifier noise, dark current noise, and thermal noise due to photo detector shunt resistance, become less important when compared to light detection using prior art methods.

An optical interposer for providing optimal optical coupling between an optical transceiver interface and an external optical interface includes an interposer photonic integrated circuit (PIC) operably configured to couple an optical signal between the optical transceiver interface and the external optical interface, one or more waveguide based optical devices operably integrated on a common substrate and one or more of interposer input/output (I/O) channels operably configured with the optical transceiver interface and the external optical interface.