In order to prevent a signal which a terminal station does not require from being intercepted by the terminal station without greatly changing the power of optical signals to be transmitted from a node to the terminal station, a node device is provided with: a first optical unit which outputs a first optical signal received from a first terminal station and addressed to a second terminal station, and a second optical signal received from the first terminal station, addressed to a third terminal station, and having a different wavelength band from the first optical signal; and a second optical unit to which the first and second optical signals outputted from the first optical unit are inputted, and which shifts the frequency of the first optical signal by a predetermined amount to create a fourth optical signal, passes the second optical signal without any change, couples the second and fourth optical signals, and transmits a resultant signal to the third terminal station.

The invention relates to a directional coupling-type multi-drop bus of which the impedance is matched with the bus at the time of coupling so that the speed is increased. A directional coupler is formed when a second module provided with a second coupler end is mounted on a first module provided with a first coupler end, and as a result, the coupling impedance where the proximity effects in the coupling state of the directional coupler are reflected is matched with the impedance of the bus.

An optical filter includes a ring resonator, an optical waveguide configured to be optically coupled to the ring resonator, and a heater provided at the ring resonator. The ring resonator includes a first curved portion. The optical waveguide includes a second curved portion. The first curved portion and the second curved portion are configured to form a directional coupler. The heater is disposed above the directional coupler.

A method of testing a photonic device includes providing a plurality of optical test signals at respective inputs of a first plurality of inputs of an optical input circuit located on a substrate, combining the plurality of optical test signals into a combined optical test signal at an output of the optical input circuit, transmitting the combined optical test signal through the output to an input waveguide of an optical device under test, the optical device under test being located on the substrate, and measuring a response of the optical device under test to the combined optical test signal. Each of the plurality of optical test signals comprises a respective dominant wavelength of a plurality of dominant wavelengths.

Exemplary apparatus can be provided which can include a laser arrangement that is configured to provide a laser radiation, and including an optical cavity. The optical cavity can include a dispersive optical waveguide first arrangement having first and second sides, and which is configured to (i) receive at least one first electromagnetic radiation at the first side so as to provide at least one second electro-magnetic radiation, and (ii) to receive at least one third electro-magnetic radiation at the second side so as to provide at least one fourth electro-magnetic radiation. The first and second sides are different from one another, and the second and third radiations are related to one another. The optical cavity can also include an active optical modulator second arrangement which can be configured to receive and modulate the fourth radiation so as to provide the first electro-magnetic radiation to the first arrangement. The laser radiation can be associated with at least one of the first, second, third or fourth radiations.

System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.

An MCF coupling device includes: a first MCF, a second MCF, and a third MCF, each of MCFs including cores; a first optical collimator that converts light output from cores included in the first MCF individually into collimated light and generates a group of light beams constituted of the collimated light; a first optical splitter that splits at least a part of the group of light beams, at a predetermined split ratio, in a first direction and in a second direction; a second optical collimator that couples each of beams of collimated light contained in the group of light beams being output in the first direction individually into cores in the second MCF; and a third optical collimator that couples each of beams of collimated light contained in the group of light beams being output in the second direction individually into cores in the third MCF.

A method of testing a photonic device includes providing a plurality of optical test signals at respective inputs of a first plurality of inputs of an optical input circuit located on a substrate, combining the plurality of optical test signals into a combined optical test signal at an output of the optical input circuit, transmitting the combined optical test signal through the output to an input waveguide of an optical device under test, the optical device under test being located on the substrate, and measuring a response of the optical device under test to the combined optical test signal. Each of the plurality of optical test signals comprises a respective dominant wavelength of a plurality of dominant wavelengths.

System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.

There is provided a separation filter. The separation filter includes: an optical circulator including first to fourth ports; a first fiber Bragg grating connected to the second port, reflecting a wavelength component of a signal input through the first and second ports corresponding to a quantum signal to output toward the second port; a first angle-cleaved fiber having a first end and connected to the first fiber Bragg grating and a second end angle-cut; a second fiber Bragg grating connected to the third port and reflecting a wavelength component of a signal input through the second and third ports corresponding to the quantum signal to output toward the third port; and a second angle-cleaved fiber having a first end connected to the second fiber Bragg grating and a second end angle-cut, wherein the quantum signal input through the third port is output through the fourth port.