An optical phase-shifting device includes a ribbed waveguide portion on an insulating layer, the waveguide portion having a p-n or p-i-n junction extending in a longitudinal direction and having a height. A pair of slab portions are disposed adjacent the waveguide portion, one on each side of the ribbed waveguide portion and on the insulation layer. The slab portion have higher doping concentrations than the respective doping concentrations in the ribbed waveguide portion. At least a portion of each slab portion has a height increasing with distance from the waveguide portion, with the slab height being smaller than that of the waveguide portion at the junction between the waveguide portion and slab portion. A pair of contact portions are formed adjacent the respective slab portion and further away from the waveguide portion. A portion of each contact portion can also have a height varying with distance from the waveguide portion.

The present invention relates to an optical component comprising a liquid crystal (LC) medium, operable in the infrared region of the electromagnetic spectrum. The invention further relates to the use of said LC medium in the infrared (IR) region and to devices comprising said optical component. The present invention further relates to an LC medium comprising one or more compounds of the formulae I, II, and III

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in which the occurring groups and parameters have the meanings defined in claim 1, and preferably one or more compounds of the formula RO

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in which the occurring groups and parameters have the meanings defined in claim 2.

An optical device (20) includes an electro-optical layer, including a liquid crystal material (24) with a heliconical structure having a pitch that is less than 250 nm and is modifiable by an electric field. An array of excitation electrodes (28) extends over the electro-optical layer. Control circuitry (23) is coupled to apply control voltage waveforms to the excitation electrodes and is configured to modify the control voltage waveforms so as to locally modify a molecule director angle of the heliconical structure and thus to generate a specified phase modulation profile in the electro-optical layer.

A magnetic field sensor comprises a magnetically responsive light propagating component configured to cause a polarization of light propagating inside the component to be rotated in response to an applied magnetic field, wherein the magnetically responsive light propagating component is formed of a bulk material doped with a dopant, the dopant including at least gadolinium, the dopant concentration being at a sufficiently low concentration such that the dopant is uniformly dispersed in the bulk material to provide a high Verdet constant. The magnetic field sensor also comprises a detector, and a polarization-maintaining light input device to couple the light into the magnetically responsive light propagating component. The detector is configured to measure a property of light output from the magnetically responsive light propagating component to determine a change in polarization of the light, the change caused by the presence of a magnetic field.

A light modulating device is disclosed herein. In some embodiments, a light modulating device includes a light modulation film layer, wherein the light modulation film layer includes a first substrate, a second substrate, and a liquid crystal layer, wherein the liquid crystal layer is disposed between the first and second substrates, wherein the liquid crystal layer and is capable of implementing twisted orientation, and wherein a K value is in a range of 0.15 to 0.4. The light modulation device can stably maintain designed optical properties even after an encapsulation process in which a pressure is applied, such as an autoclave process. The light modulating device can also stably maintain the orientation state of the light modulation layer while effectively securing adhesive force between upper and lower substrates.

An electrically controlled polarization rotator is disclosed. The electrically controlled polarization rotator includes two substrates and a liquid crystal layer located between the two substrates. The two substrates have a homogeneous alignment and a homeotropic alignment respectively. A distance between the two substrates is a liquid crystal thickness. A switching electric field which is adjustable is provided between the two substrates. A polarized light is incident on the substrate having the homogeneous alignment. A polarization direction of the polarized light is orthogonal or parallel to an alignment direction of the substrate having the homogeneous alignment. A birefringence of the liquid crystal layer multiplied by the liquid crystal thickness and further divided by a wavelength of the polarized light is greater than 10. The polarization direction of the polarized light is rotated corresponding to an intensity of the switching electric field in the liquid crystal layer.

Examples described herein relate to an optical device that entails phase shifting an optical signal. The optical device includes an optical waveguide having a first semiconductor material region and a second semiconductor material region formed adjacent to each other and defining a junction therebetween. Further, the optical device includes an insulating layer formed on top of the optical waveguide. Moreover, the optical device includes a III-V semiconductor layer formed on top of the insulating layer causing an optical mode of an optical signal passing through the optical waveguide to overlap with the first semiconductor material region, the second semiconductor material region, the insulating layer, and the III-V semiconductor layer thereby resulting in a phase shift in the optical signal passing through the optical waveguide.

An electro-optical phase modulator includes a waveguide made from a stack of strips. The stack includes a first strip made of a doped semiconductor material of a first conductivity type, a second strip made of a conductive material or of a doped semiconductor material of a second conductivity type, and a third strip made of a doped semiconductor material of the first conductivity type. The second strip is separated from the first strip by a first interface layer made of a dielectric material, and the third strip is separated from the second strip by a second interface layer made of a dielectric material.

A projection type transparent display includes a polarization modulator and a reflective layer. The polarization modulator is stacked in sequence by a linear polarizer, a liquid crystal layer and a phase retarder. The reflective layer is stacked on the phase retarder. A projection light is incident on the linear polarizer to form a linearly polarized light. The liquid crystal layer changes a polarization direction of the linearly polarized light. Two kinds of linearly polarized projection lights with polarization directions orthogonal to each other are respectively formed and pass through the phase retarder to respectively form two kinds of circularly polarized projection lights with opposite rotation directions. A background light is incident on the reflective layer. A circularly polarized background light with the same spiral direction is reflected, and the circularly polarized background light opposite to the spiral direction passes through the reflective layer and is incident on the polarization modulator.

The embodiments herein relate to electrochromic stacks, electrochromic devices, and methods and apparatus for making such stacks and devices. In various embodiments, an anodically coloring layer in an electrochromic stack or device is fabricated to include nickel-tungsten-tin-oxide (NiWSnO). This material is particularly beneficial in that it is very transparent in its clear state.