A head-mounted light field display device, the device comprising at least one multiplexed light field display module adapted to face an eye of a viewer wearing the device, the multiplexed light field display module comprising a light field view image generator and a waveguide with a set of shutters, the light field view image generator operable to generate, over time, a set of beams of light from a different one of a set of light field view images, the shuttered waveguide operable to transmit the set of beams and to open, over time, a different subset of the set of shutters, the subset corresponding to a position associated with the view image, thereby to emit the set of beams via the subset, thereby to display to the viewer a time-varying optical light field representative of the set of view images.

The present disclosure provides an optical coherent imager implemented on a photonic integrated circuit (PIC) that enables shared path for transmitting and receiving optical signals by exploiting polarization diversity. The present disclosure also provides an optical coherent imager including an array of the optical coherent sensing units to simplify the design and calibrations of the imager, and a method for coherent sensing by the optical coherent imager.

Many embodiments in accordance with the invention are directed towards waveguides implementing birefringence control. In some embodiments, the waveguide includes a birefringent grating layer and a birefringence control layer. In further embodiments, the birefringence control layer is compact and efficient. Such structures can be utilized for various applications, including but not limited to: compensating for polarization related losses in holographic waveguides; providing three-dimensional LC director alignment in waveguides based on Bragg gratings; and spatially varying angular/spectral bandwidth for homogenizing the output from a waveguide. In some embodiments, a polarization-maintaining, wide-angle, and high-reflection waveguide cladding with polarization compensation is implemented for grating birefringence. In several embodiments, a thin polarization control layer is implemented for providing either quarter wave or half wave retardation.

A light polarisation converter for a photonic integrated circuit, comprising: a substrate and a waveguide. The substrate comprises a first surface and a second surface. The waveguide comprises a first waveguide portion in contact with the first surface, and a second waveguide portion in contact with the second surface. The second surface is offset from the first surface along a first axis and a second axis. Each axis is perpendicular to a light propagation direction for converting polarisation of the light. The second waveguide portion is offset from the first waveguide portion.

In an example, a photonic system includes a Si PIC with a Si substrate, a SiO.sub.2 box formed on the Si substrate, a first layer, and a second layer. The first layer is formed above the SiO.sub.2 box and includes a SiN waveguide with a coupler portion at a first end and a tapered end opposite the first end. The second layer is formed above the SiO.sub.2 box and vertically displaced above or below the first layer. The second layer includes a Si waveguide with a tapered end aligned in two orthogonal directions with the coupler portion of the SiN waveguide such that the tapered end of the Si waveguide overlaps in the two orthogonal directions and is parallel to the coupler portion of the SiN waveguide. The tapered end of the SiN waveguide is configured to be adiabatically coupled to a coupler portion of an interposer waveguide.

A micro-ring resonator includes at least one first straight waveguide; a second waveguide (Arm3) and a third waveguide (Arm2), where the second waveguide (Arm3) and the third waveguide (Arm2) form a closed annular waveguide, and the annular waveguide is coupled to the first waveguide; a fourth waveguide (Arm1), where the fourth waveguide (Arm1) is coupled to the annular waveguide; and a polarization splitter (PS), where one end of the polarization splitter (PS) is connected to the fourth waveguide (Arm1), and one end is connected to the second waveguide (Arm3) in the annular waveguide. In the micro-ring resonator, a distance between two waveguides for separately transmitting different polarized light breaks a limitation of a resonator radius, and further, a distance between a TE path and a TM path is reduced.

A medical instrument is described that includes an optical source, an optical fiber, and a waveguide patterned upon a substrate. The optical fiber receives radiation from the optical source and includes a first segment and a second segment. The second segment is rotated about an optical axis relative to the first segment. The waveguide receives radiation from the optical source and guides a beam of radiation. The waveguide includes a first waveguide segment designed to impart a first differential group delay on the beam of radiation and a second waveguide segment designed to impart a second differential group delay on the beam of radiation. A sum of the first differential group delay and the second differential group delay is substantially zero.

A path-switchable dual polarization controller includes an input polarization beam splitter (PBS) switchably connected to either one of two optical controllers configured to tunably remix polarization components received from the PBS to obtain two target polarization components of input light. When one of the optical controllers requires a reset, PBS outputs are switched to the other optical controller, and the first optical controller is reset offline. The circuit may be used for polarization demultiplexing.

A head-mounted light field display device, the device comprising at least one multiplexed light field display module adapted to face an eye of a viewer wearing the device, the multiplexed light field display module comprising a light field view image generator and a waveguide with a set of shutters, the light field view image generator operable to generate, over time, a set of beams of light from a different one of a set of light field view images, the shuttered waveguide operable to transmit the set of beams and to open, over time, a different subset of the set of shutters, the subset corresponding to a position associated with the view image, thereby to emit the set of beams via the subset, thereby to display to the viewer a time-varying optical light field representative of the set of view images.

An apparatus of polarization self-compensated delay line interferometer. The apparatus includes a first waveguide arm of a first material of a first length disposed between an input coupler and an output coupler and a second waveguide arm of the first material of a second length different from the first length disposed between the same input coupler and the same output coupler. The apparatus produces an interference spectrum with multiple periodic passband peaks where certain TE (transverse electric) and TM (transverse magnetic) polarization mode passband peaks are lined up. The apparatus further includes a section of waveguide of a birefringence material of a third length added to the second waveguide arm to induce a phase shift of the lined-up TE/TM passband peaks to a designated grid as corresponding polarization compensated channels of a wide optical band.