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.

A depolarizer for a broadband optical source to split the source beam by power, not by polarization state, and route the components into respective light paths. A polarization rotator arranged in one of the light paths rotates the polarization state of that beam component to make it orthogonal to that of the other. The components are then recombined by a combiner and output. A variable optical attenuator is arranged in one of the light paths, which during operation is adjusted by a controller to maintain power equalization between the light paths and hence depolarization performance. The controller receives power measurements from the light paths and from after the combiner via respective sensors. With this feedforward design reminiscent of a Mach-Zehnder interferometer the light from a light source which generates highly polarized light can be depolarized in theory with zero insertion loss and in practice with losses of about 1 dB.

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.

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 an example, a polarization control system is to manipulate polarization manipulators to output light that achieves a trajectory on a Poincar sphere that tracks a known trajectory of a polarizer on the Poincar 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.

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 Poincar 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 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 depolarizer for a broadband optical source to split the source beam by power, not by polarization state, and route the components into respective light paths. A polarization rotator arranged in one of the light paths rotates the polarization state of that beam component to make it orthogonal to that of the other. The components are then recombined by a combiner and output. A variable optical attenuator is arranged in one of the light paths, which during operation is adjusted by a controller to maintain power equalization between the light paths and hence depolarization performance. The controller receives power measurements from the light paths and from after the combiner via respective sensors. With this feedforward design reminiscent of a Mach-Zehnder interferometer the light from a light source which generates highly polarized light can be depolarized in theory with zero insertion loss and in practice with losses of about 1 dB.

There is provided a system and method for providing privacy viewing of an output from a electronic display, including a first polarizer configured to polarize a display signal at a first polarization angle; a second polarizer configured to polarize a noise signal at a second polarization angle orthogonal to the first polarization angle; a combiner configured to combine the polarized display signal and the polarized noise signal, and a third polarizer configured to receive the output of the electronic display and polarize the combined polarized display and noise signal at the first polarization angle. The system includes first and second polarization rotators configured to rotate the first and second polarization angles of the combined polarized display and noise signals prior to being output by the electronic display and prior to being received by the third polarizer.