An apparatus is described. The apparatus comprises a downstream wavelength selective switch having an input port, an optical path operable to carry an optical signal, an optical source providing amplified spontaneous emission (ASE) light, an optical switch having a first input coupled to the optical path, a second input coupled to the optical source and receiving the ASE light, and an output coupled to the input port of the downstream wavelength selective switch. The optical switch couples either the first input or the second input to the output. Further included is a photodiode operable to monitor the optical signal, detect an optical loss of signal of the optical signal, and output a switch signal to the optical switch such that the optical switch couples the second input receiving the ASE light to the output whereby the ASE light is directed to the input port of the downstream wavelength selective switch.

An apparatus is described. The apparatus comprises a downstream wavelength selective switch having an input port, an optical path operable to carry an optical signal, an optical source providing amplified spontaneous emission (ASE) light, an optical switch having a first input coupled to the optical path, a second input coupled to the optical source and receiving the ASE light, and an output coupled to the input port of the downstream wavelength selective switch. The optical switch couples either the first input or the second input to the output. Further included is a photodiode operable to monitor the optical signal, detect an optical loss of signal of the optical signal, and output a switch signal to the optical switch such that the optical switch couples the second input receiving the ASE light to the output whereby the ASE light is directed to the input port of the downstream wavelength selective switch.

Provided is an optical modulator including: a relay substrate; a first transmission line that is provided on a flat surface of the relay substrate, and transmits, along the flat surface of the relay substrate, an electrical signal that has been input from an outer side; a second transmission line that is provided in the relay substrate, and transmits the electrical signal in a direction that is not included in the flat surface; a modulation unit that modulates an optical signal by using the electrical signal that is transmitted by the first transmission line and the second transmission line; and a shield that shields a radiation component of the electrical signal that is radiated from a contact of the first transmission line and the second transmission line.

Electro-optic devices for classical and quantum microwave photonics are provided. In various embodiments, a device comprises: a waveguide; a first ring resonator; a second ring resonator, the second ring resonator evanescently coupled to the first ring resonator and to the waveguide; a first pair of electrodes, one of the first pair of electrodes disposed within the first ring resonator and the other of the first pair of electrodes disposed without the first ring resonator; a second pair of electrodes, one of the second pair of electrodes disposed within the second ring resonator and the other of the second pair of electrodes disposed without the second ring resonator; a microwave source electrically coupled to the first and second pairs of electrodes; a bias port electrically coupled to the first and second pairs of electrodes and configured to sweep a frequency band.

An optical device is provided, which includes: an optical waveguide provided in a substrate having an electro-optic effect; a signal electrode provided on the substrate and above the optical waveguide; and a peeling prevention film which is provided on at least a part of an outer peripheral portion of the substrate and at a position spaced apart from the signal electrode, and also serves as a ground electrode.

A method for manufacturing an electro-optically coupled switch in accordance with the present invention requires a sequential reconfiguration of a layer of semiconductor material. To begin, a base member is created wherein the semiconductor layer is positioned on a layer of insulator material with the insulator material positioned between the semiconductor layer and a semiconductor substrate. In sequence, with a first etch, the semiconductor layer is etched to create waveguides on opposite sides of a slot. In a second etch, the slot is deepened to expose the layer of insulator material in the slot. With a third contact pad doping process, pads can be positioned on top of the layer of insulator material for electrical contact with the respective waveguides. Metal contacts can then be placed on the contact pads, the slot can be filled with an electro-optical polymer and, if needed, the polymer can be poled.

A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

A two-dimensional photonic crystal in which are inserted four waveguides and a resonant cavity. Owing to the existence of the photonic band gap, an electromagnetic signal propagating through the device is confined within the guides and the cavity and, through the adjustment of the orientation of a dipole mode generated within the cavity, is able to function in three distinct regimes. In regime 1, subjected to an external DC magnetic field +H0, it functions as a two-way divider, with isolation of the input relative to the two outputs, and, upon reversal of the field signal, it functions as an optical key. In regime 2, with the use of a DC magnetic field −H0, it functions as a waveguide bender, with the input isolated from the output, and, upon reversal of the field signal, functions as an optical key. In regime 3, subject to the application of an external DC magnetic field +H1, the device functions as a three-way divider.

A two-dimensional photonic crystal in which are inserted four waveguides and a resonant cavity. Owing to the existence of the photonic band gap, an electromagnetic signal propagating through the device is confined within the guides and the cavity and, through the adjustment of the orientation of a dipole mode generated within the cavity, is able to function in three distinct regimes. In regime 1, subjected to an external DC magnetic field +H0, it functions as a two-way divider, with isolation of the input relative to the two outputs, and, upon reversal of the field signal, it functions as an optical key. In regime 2, with the use of a DC magnetic field −H0, it functions as a waveguide bender, with the input isolated from the output, and, upon reversal of the field signal, functions as an optical key. In regime 3, subject to the application of an external DC magnetic field +H1, the device functions as a three-way divider.