An optical switch device includes a first semiconductor structure configured to operate as a first waveguide and a second semiconductor structure configured to operate as a second waveguide. The second semiconductor structure is located above or below the first semiconductor structure and separated from the first semiconductor structure. The second semiconductor structure includes a first portion having a first width and a second portion having a width different from the first width and located on the first portion. The first portion is located between a first doped region and a second doped region.

Methods, systems, and devices for quantum key distribution (QKD) in passive optical networks (PONs) are described. A PON may be a point-to-multipoint system and may include a central node in communication with multiple remote nodes. In some cases, each remote node may include a QKD transmitter configured to generate a quantum pulse indicating a quantum key, a synchronization pulse generator configured to generate a timing indication of the quantum pulse, and filter configured to output the quantum pulse and the timing indication to the central node via an optical component (e.g., an optical splitter, a cyclic arrayed waveguide grating (AWG) router). The central node may receive the timing indications and quantum pulses from multiple remote nodes. Thus, the central node and remote nodes may be configured to communicate data encrypted using quantum keys.

Methods, systems, and devices for quantum key distribution (QKD) in passive optical networks (PONs) are described. A PON may be a point-to-multipoint system and may include a central node in communication with multiple remote nodes. In some cases, each remote node may include a QKD transmitter configured to generate a quantum pulse indicating a quantum key, a synchronization pulse generator configured to generate a timing indication of the quantum pulse, and filter configured to output the quantum pulse and the timing indication to the central node via an optical component (e.g., an optical splitter, a cyclic arrayed waveguide grating (AWG) router). The central node may receive the timing indications and quantum pulses from multiple remote nodes. Thus, the central node and remote nodes may be configured to communicate data encrypted using quantum keys.

There is provided an illumination device comprising: a laser; a waveguide comprising at least first and second transparent lamina; a first grating device for coupling light from the laser into a TIR path in the waveguide; a second grating device for coupling light from the TIR path out of the waveguide; and a third grating device for applying a variation of at least one of beam deflection, phase retardation or polarization rotation across the wavefronts of the TIR light. The first second and third grating devices are each sandwiched by transparent lamina.

A photonic heater is provided. The photonic heater includes a current source and a transfer circuit. The transfer circuit connected to the current source. The photonic heater further includes a heating element. The heating element is connected to the transfer circuit. The transfer circuit is operable to regulate an amount of current being transferred from the current court to the heating element.

A photonic heater is provided. The photonic heater includes a current source and a transfer circuit. The transfer circuit connected to the current source. The photonic heater further includes a heating element. The heating element is connected to the transfer circuit. The transfer circuit is operable to regulate an amount of current being transferred from the current court to the heating element.

One illustrative device disclosed herein includes a lower waveguide structure and an upper body structure positioned above at least a portion of the lower waveguide structure. In this example, the device also includes a grating structure positioned in the upper body structure, wherein the grating structure comprises a plurality of grating elements that comprise a tunable material whose index of refraction may be changed by application of energy to the tunable material.

One illustrative device disclosed herein includes a lower waveguide structure and an upper body structure positioned above at least a portion of the lower waveguide structure. In this example, the device also includes a grating structure positioned in the upper body structure, wherein the grating structure comprises a plurality of grating elements that comprise a tunable material whose index of refraction may be changed by application of energy to the tunable material.

A waveguide component includes a waveguide, which is at least partially transparent or translucent with respect to light and is set up in such a way that light can be conducted at least partially through the waveguide. The waveguide includes a waveguide core, a first casing region, and a second casing region. The waveguide core is formed from one or more spatially separated elements of at least one waveguide core material. The first casing region, which includes at least one electro-optical material, interacts with light guided in the waveguide. The first casing region is disposed around the one or more elements of the waveguide core. The second casing region includes at least one dielectric material. The second casing region is arranged around the first casing region and/or the waveguide core. The waveguide component further includes at least two line regions that are at least partially electrically conductive.

A photonic heater is provided. The photonic heater includes a current source and a transfer circuit. The transfer circuit connected to the current source. The photonic heater further includes a heating element. The heating element is connected to the transfer circuit. The transfer circuit is operable to regulate an amount of current being transferred from the current court to the heating element.