An optical resonator system comprises an optical resonator (30) and means (32, 42, 44) for coupling into the resonator counterpropagating waves at total intensities such as to produce a non-linear interaction between the first and second waves whereby to break the symmetry to establish different resonant frequencies between the first and second counterpropagating waves whereby to produce different optical effects in the opposite directions. A common light source, e.g. a laser 32, is employed with an amplifier 40 and a modulator 50, or different light sources can be employed.

Techniques are described for using confinement structures and/or pattern gratings to reduce or prevent the wicking of sealant polymer (e.g., glue) into the optically active areas of a multi-layered optical assembly. A multi-layered optical structure may include multiple layers of substrate imprinted with waveguide grating patterns. The multiple layers may be secured using an edge adhesive, such as a resin, epoxy, glue, and so forth. A confinement structure such as an edge pattern may be imprinted along the edge of each layer to control and confine the capillary flow of the edge adhesive and prevent the edge adhesive from wicking into the functional waveguide grating patterns of the layers. Moreover, the edge adhesive may be carbon doped or otherwise blackened to reduce the reflection of light off the edge back into the interior of the layer, thus improving the optical function of the assembly.

An electronic device that has an optical modulation region and a non-optical modulation region is provided, and the electronic device includes a first substrate, a first transparent electrode layer, and a second transparent electrode layer. The first transparent electrode layer is disposed on the first substrate. The second transparent electrode layer is disposed on the first transparent electrode layer and has an opening. The optical modulation region overlaps the opening, and the non-optical modulation region overlaps the first transparent electrode layer and the second transparent electrode layer. A cell gap of the optical modulation region is greater than a cell gap of the non-optical modulation region.

An optical switch is disclosed which is electrically activatable through received photon energy. The switch may include a substrate responsive to photon energy that forms an optical excitation signal. First and second electrodes may be disposed on first and second surfaces of the substrate. The substrate may have a characteristic of two-photon absorption to enable electrical conduction through the substrate, the two-photon absorption being enhanced by deep energy levels located in a bandgap between conductance and valence bands of the substrate, which are at least near resonant with the photon energy.

A controller for use in a power converter including a jitter generator circuit coupled to receive a drive signal from a switch controller and generate a jitter signal. The jitter signal is a modulated jitter signal when the drive signal is below a first threshold frequency. The switch controller is coupled to a power switch coupled to an energy transfer element. The switch controller is coupled to receive a current sense signal representative of a current through the power switch. The switch controller is coupled to generate the drive signal to control switching of the power switch in response to the current sense signal and the jitter signal to control a transfer of energy from an input of the power converter to an output of the power converter.

A light emitting apparatus includes: a semiconductor layer including a light emitting region that generates modulation light modulated with a first signal, and a feedback region that is configured so that a feedback mode to feed back a part of light generated in the light emitting region to the light emitting region and a monitor mode to monitor a light amount of the light generated in the light emitting region are switchable; and a controller, wherein when the modulation light is generated in the light emitting region, the controller sets the feedback region to the feedback mode, and the controller switches the feedback region to the monitor mode during at least a part of a period in which there is no first signal.

An optical switch is disclosed which is electrically activatable through received photon energy. The switch may include a substrate responsive to photon energy that forms an optical excitation signal. First and second electrodes may be disposed on first and second surfaces of the substrate. The substrate may have a characteristic of two-photon absorption to enable electrical conduction through the substrate, the two-photon absorption being enhanced by deep energy levels located in a bandgap between conductance and valence bands of the substrate, which are at least near resonant with the photon energy.

A controller for use in a power converter includes a jitter generator circuit coupled to receive a drive signal from a switch controller and generate a jitter signal. The switch controller is coupled to a power switch coupled to an energy transfer element. The switch controller is coupled to receive a current sense signal representative of a drain current through the power switch. The switch controller is coupled to generate the drive signal to control switching of the power switch in response to the current sense signal and the jitter signal to control a transfer of energy from an input of the power converter to an output of the power converter.

A wideband ultra-high refractive index mesoscopic crystal structure using space-filling of an electric dipole according to one aspect of the present disclosure includes: a first layer in which a plurality of high-conductivity unit bodies is arranged in a matrix form, and a low-conductivity material is disposed between the high-conductivity unit bodies to insulate the high-conductivity unit bodies from each other; a second layer in which a plurality of high-conductivity unit bodies is arranged in a matrix form, and a low-conductivity material is disposed between the high-conductivity unit bodies to insulate the high-conductivity unit bodies from each other, the second layer being adjacent to the first layer; and a shield layer existing between the first and second layers and made of a low-conductivity material, wherein the high-conductivity unit bodies in the first layer overlap the plurality of high-conductivity unit bodies arranged in the second layer, and a stack in which the first layer, the shield layer, the second layer, and the shield layer are sequentially stacked is repeated one or more times.

Disclosed are a robust polarization-entangled quantum source from an atomic ensemble and an implementation method. A robust polarization-entangled quantum source from an atomic ensemble according to an example embodiment includes an atomic vapor cell containing rubidium (.sup.87Rb) atoms, and a processor configured to generate a photon pair of a signal and an idler from the atomic vapor cell by traveling a coupling laser and a pump laser in opposite directions with respect to the atomic vapor cell.