A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

According to examples, a system for measuring polarization dependent loss (PDL) for a device-under-test (DUT) may include a tunable laser, a polarization element and a power meter. The tunable laser may emit an optical signal to sweep across an optical band at a constant rate. The polarization element may scramble polarizations states of the optical signal emitted from the tunable laser. The power meter may take power measurements associated with the optical signal emitted from the tunable laser, wherein the power measurements from the power meter are used to determine a maximum insertion loss (IL) and a minimum insertion loss (IL) associated with the device-under-test (DUT). An average insertion loss (IL) and a polarization dependent loss (PDL) for the device-under-test (DUT) may be calculated based on the maximum insertion loss (IL) and the minimum insertion loss (IL) associated with the device-under-test (DUT).

A lightguide optical element (LOE) configured for polarization scrambling is provided. The LOE includes a transparent substrate having a first refractive index, the substrate having a pair of parallel external surfaces configured to propagate light within the LOE through total internal reflection (TIR), and a plurality of mutually parallel partially reflective internal surfaces, those being non-parallel to the pair of parallel external surfaces and configured to couple out said light to a viewer. The LOE further includes a first coating on at least one external surface of the substrate, the first coating being of a coating material having a second refractive index higher than the first refractive index; The LOE further includes an antireflective (AR) coating on at least one external surface of the substrate over the first coating.

A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization to scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

According to an example, a polarization control system is to manipulate polarization manipulators to output light that achieves a trajectory on a Poincaré sphere that tracks a known trajectory of a polarizer on the Poincaré sphere, in which the trajectory of the output light enables definition of a reference polarization state of the output light. The polarization control system may also manipulate an output polarization manipulator to set the output light to a predefined polarization state based upon the reference polarization state.

A lightguide optical element (LOE) configured for polarization scrambling is provided. The LOE includes a transparent substrate having a first refractive index, the substrate having a pair of parallel external surfaces configured to propagate light within the LOE through total internal reflection (TIR), and a plurality of mutually parallel partially reflective internal surfaces, those being non-parallel to the pair of parallel external surfaces and configured to couple out said light to a viewer. The LOE further includes a first coating on at least one external surface of the substrate, the first coating being of a coating material having a second refractive index higher than the first refractive index; The LOE further includes an antireflective (AR) coating on at least one external surface of the substrate over the first coating.

A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization to scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

The disclosed matter provides integrated metasurface devices for conversion between a waveguide mode and a free-space optical wave with a designer wavefront. In exemplary embodiments, the integrated metasurface devices include a thin waveguide, a waveguide taper, a leaky-wave metasurface defined within a high refractive index layer of dielectric material, and a low refractive index substrate. The device can manipulate all the four optical degrees of freedom of the free-space wavefront, namely: amplitude, phase, polarization orientation, and polarization ellipticity, by using a leaky-wave metasurface composed of meta-units with four structural degrees of freedom.

Devices, systems and methods are described that efficiently convert an incident light having a particular polarization into light having a plurality of polarizations that are distributed according to a particular pattern. For example, the output light can have a plurality of plurality of polarization states that are randomly distribute over the Poincaré sphere. One polarization scrambler includes a plurality of polarization elements positioned to receive polarized or partially polarized light. Each polarization element includes a half waveplate to rotate a polarization direction of the polarized or partially polarized light, and a quarter waveplate to receive light that exits the first layer and to change a polarization state of the light that exits the first layer to another polarization state. The polarization scrambler further includes a substrate to receive the light after exiting the quarter waveplate, and to provide the output light that includes a plurality of polarization states.

A Faraday-based polarization scrambler is disclosed. The Faraday-based polarization scrambler may comprise a first toroidal assembly. The first toroidal assembly may include an optical fiber that is looped to form a first looped portion, and a first electrical wire that coils around the first looped portion to form a first toroidal configuration. In some examples, the first electrical wire may be connected to a voltage source and carries a current to form a magnetic field within the first toroidal configuration. In some examples, there may be additional toroidal assemblies provided to the Faraday-based polarization scrambler. One or more of these toroidal assemblies may create an actuation field to effect modulation for polarization scrambling and emulation that mitigates polarization-dependent effects.