A polarization converter based on taking a high-order TE mode as a transition mode comprises a ridge waveguide (1) and a slab waveguide (2) that are arranged in double layers and varying in width, and a strip waveguide (4) which is varying in width. The ridge waveguide (1) is disposed on the upper end face of the slab waveguide (2), and is aligned with two ends of the slab waveguide (2). The right end of the ridge waveguide (1) and the slab waveguide (2) are connected with the strip waveguide (4) with the varying width. A TM.sub.0 mode enters from the left ends of the ridge waveguide and the slab waveguide, and is converted into a TE.sub.0 mode for output. On the contrary, the TE.sub.0 mode enters from the right end of the strip waveguide and is converted into the TM.sub.0 mode for output.

Methods for design and production of highly sensitive active and passive light detecting devices and systems. Orders of magnitude improvement in optical signal detection is made possible in high noise or low contrast scenes. The current invention creates a small spectral difference between two parts of a split light stream. When recombined, the altered light streams partially correlate, and that generates full amplitude signal oscillation at a frequency that depends on the constituent spectrum. The full amplitude signals and spectrum dependent oscillation make signal discrimination much better than intensity-only methods. The effect of read noise, amplifier noise, dark current noise, and thermal noise due to photo detector shunt resistance, become less important when compared to light detection using prior art methods

A polarization splitter-rotator (PSR) is described. The PSR having a silicon nitride based waveguide to split and rotate an optical beam. The silicon nitride based waveguide having a first silicon nitride segment including a first layer and a second layer coupled with the first layer.

Embodiments described herein may be related to apparatuses, processes, and techniques related to a dual polarization chiplet that may be used by an optical receiver to split multi-polarized light traveling on a single fiber and carrying two or more light signals into two or more fibers each carrying the particular light signal. The dual polarization chiplet may also be used by an optical transmitter to combine multiple light signals to be transmitted onto a single fiber, where each of the multiple light signals are represented by a different polarization of a wavelength on the single fiber. Other embodiments may be described and/or claimed.

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.

Apparatuses and methods associated with silicon photonic chips, are disclosed herein. In some embodiments, a quarter wave plate (QWP) is provided to a silicon photonic chip to convert a first linearly polarized mode (e.g., TE mode) optical beam from a laser disposed on the silicon photonic chip, into a combination of orthogonal polarization modes optical beam, and to convert or contribute in converting a reflection of the combined polarized modes optical beam into a second linearly polarized mode (e.g., TM) optical beam with polarization orthogonal to the first. The optical beam is rotated relative to an axis of the QWP, or the QWP and its axis are rotated relative to a polarization axis of the optical beam. Other embodiments are also described and claimed.

A photonic integrated circulator can be fabricated by including a plurality of polarizing beam splitters and optical polarization rotators such that two copies of the optical signal are output at a receiver in substantially aligned polarization states. The circulator can be used for facilitating bi-directional communications between photonic integrated circuit devices, which are inherently polarization sensitive, while reducing signal loss.

Photonic devices are disclosed including a first cladding layer, a first electrical contact comprising a first lead coupled to a first dielectric portion, a second electrical contact comprising a second lead coupled to a second dielectric portion, a waveguide structure comprising a slab layer comprising a first material, and a second cladding layer. The slab layer may be coupled to the first dielectric portion of the first electrical contact and the second dielectric portion of the second electrical contact. The first dielectric portion and the second dielectric portion may have a dielectric constant greater than a dielectric constant of the first material.

A magnetic field sensor element 30 has a first polarization maintaining fiber 31 separating the linearly polarized light into a first linearly polarized wave propagated along the first slow axis and a second linearly polarized wave propagated along the first phase advance axis faster than the first linearly polarized wave, and propagating the first linearly polarized wave and the second linearly polarized wave, a second polarization maintaining fiber 32 having a second slow axis and a second phase advance axis, and connected to the first polarization maintaining fiber so that the second phase advance axis and the second slow axis are inclined 45 degrees with respect to the first phase advance axis and the first slow axis, a Faraday rotator 33 optically connected to the second polarization maintaining fiber, and shifting a phase of circularly polarized light emitted from the second polarization maintaining fiber in response to magnetic field at which the magnetic field sensor element is disposed, and a mirror element 34 connected to the Faraday rotator, and generating the return light.

The present invention discloses an encoding apparatus, including: a polarization splitter-rotator PSR, a polarization rotation structure, and a modulator, where the PSR is configured to receive an input signal light, split the input signal light into two parts whose polarization modes are the same, and send the two parts to the polarization rotation structure and the modulator respectively; the polarization rotation structure has functions of rotating, by 180 degrees, a polarization direction of an optical signal entering the polarization rotation structure from one end, and keeping a polarization direction of an optical signal entering the polarization rotation structure from the other end unchanged; the modulator is configured to modulate a light input to the modulator; and the PSR is further configured to receive signal lights sent by the polarization rotation structure and the modulator, combine the two signal lights to send the output signal light.