A PIC that includes an InP-based polarization rotator having an improved design that enables at least one of an improved performance and an improved yield of the PIC due to at least one of reduced variations in critical dimensions of the InP-based polarization rotator and reduced overlay errors during fabrication of the InP-based polarization rotator of the PIC. An opto-electronic system including said PIC. A method of fabricating the PIC that includes the InP-based polarization rotator having the improved design.

An integrated photonics polarization controller that converts an input optical signal having a TE.sub.00 mode into an output optical signal having any polarization on the Poincare sphere is disclosed. This polarization conversion and control requires splitting the input optical signal into two optical signals. The first optical signal retains its TE.sub.00 mode, while the second optical signal must have a TM.sub.00 mode, with the integrated photonics polarization controller generating this TM.sub.00 mode either directly from the TE.sub.00 mode or indirectly via an intermediate signal having a TE.sub.10 mode. The magnitude and phase of the first and second optical signals are each controlled independently. The first and second optical signals are then combined to form an output optical signal and, due to the independent control of magnitude and phase of the first and second optical signals, the output optical signal may have any polarization on the Poincare sphere.

Embodiments disclosed herein include photonics systems with a dual polarization module. In an embodiment, a photonics patch comprises a patch substrate, and a photonics die over a first surface of the patch substrate. In an embodiment, a multiplexer is over a second surface of the patch substrate. In an embodiment, a first optical path from the photonics die to the multiplexer is provided for propagating a first optical signal, and a second optical path from the photonics die to the multiplexer is provided for propagating a second optical signal. In an embodiment, a Faraday rotator is provided along the second optical path to convert the second optical signal from a first mode to a second mode before reaching the multiplexer.

An optical element comprises: a substrate including a main surface; and a core layer that is provided on the main surface. The core layer includes a mode converter that converts a polarization mode of visible light. The mode converter includes: a first waveguide to which the visible light is incident in a first polarization mode that is one polarization mode of a TE mode and a TM mode; a second waveguide that emits the visible light in a second polarization mode that is the other polarization mode of the TE mode and the TM mode; and a third waveguide provided between the first waveguide and the second waveguide, the third waveguide that converts the visible light from the first polarization mode to the second polarization mode. The third waveguide has an asymmetric shape in a second direction along the main surface, the second direction intersecting the first direction.