Radio frequency (RF) polarizer feeds and associated waveguide structures having twist features are discussed herein. In one example, a first waveguide segment spans a longitudinal axis between a feed port and a twist port and includes two stacked rounded rectangular elements skewed in minor axis alignment with respect to each other and having major axes perpendicular to the longitudinal axis. A second waveguide segment spans the longitudinal axis between the twist port and a polarizer port and is coupled to the first waveguide segment at the twist port. The second waveguide segment includes first ridge elements that span longitudinally from the twist port on first opposing walls of the second waveguide segment, and second ridge elements that span longitudinally from the twist port on second opposing walls of the second waveguide segment.

An integrated optical collimator device includes an optical fiber extending from a first end to a second end. The first end of the optical fiber is configured to be coupled to a light source or a light receiver. A housing is coupled to the ferrule and extends radially over the ferrule. A collimating lens is positioned in the housing proximate the second end of the optical fiber. A polarizer element is positioned within the housing proximate the collimating lens.

A state of polarization (SOP) controller allows a randomly polarized input beam to be converted to a single linear polarization, while transferring substantially all of the power to the output. The input beam is split into orthogonal components and one of the components rotated and a phase difference between the components compensated for. The phase aligned components may then be recombined into a single output. The phase shifters may be reset during a reset period during which the impact on data transmission is reduced.

The present disclosure provides a backlight module and a display device. The backlight module includes a light source and a light guide plate. The backlight module further includes: a light collimation element configured to convert divergent rays emitted from the light source into parallel rays; a polarizing beam-splitting element configured to convert the parallel rays into a first polarized ray and a second polarized ray with their vibration directions perpendicular to each other; and a phase delaying element configured to convert the vibration direction of the second polarized ray to be identical to that of the first polarized ray, so as to form a third polarized ray. The first and third polarized rays form incident polarized rays entering into the light guide plate. The light guide plate is configured to receive the incident polarized rays.

An optical device is provided that incorporates twin wavelength selective switches (WSSs), is compact, and avoids using a Wollaston prism. Additionally, the path lengths traversed by wavelength components through each WWS may be the same. The optical device may include a first subset and second subset of optical ports, where each of the first and second subsets can operate as an independent WSS. An optical arrangement of the optical device may support optical coupling between (i) any ports in the first subset of ports for light in a first polarization state and (ii) any ports in the second subset of ports for light in a second polarization state. The optical device may further include beam directing optics for coupling wavelength components of an optical beam from a focusing element to a programmable optical phase modulator and from the programmable optical phase modulator to the focusing element.

A head-mounted display system can include a head-mountable frame, a light projection system configured to output light to provide image content to a user's eye, and a waveguide supported by the frame. The waveguide can be configured to guide at least a portion of the light from the light projection system coupled into the waveguide to present the image content to the user's eye. The system can include a grating that includes a first reflective diffractive optical element and a second reflective diffractive optical element. The combination of the first and second reflective diffractive optical elements can operate as a transmissive diffractive optical element. The first reflective diffractive optical element can be a volume phase holographic grating. The second reflective diffractive optical element can be a liquid crystal polarization grating.