摘要:
An optical transmission device improved in quality and reliability of OADM function and permitting configuration of highly-flexible, economical OADM networks. A wavelength tunable filter variably selects a wavelength according to a control frequency. A filter controller applies the control frequency to the filter while scanning wavelength over an entire signal bandwidth, to detect, from a reference wavelength monitor signal supplied thereto, a reference control frequency which permits the filter to select a reference wavelength and according to which wavelength is matched. On receiving a wavelength selection request, the controller obtains a target control frequency from the reference control frequency and the position of a target wavelength relative to the reference wavelength, and applies the obtained frequency to the filter. A reference wavelength filter transmits the reference wavelength therethrough. A light-receiving element monitors the transmitted reference wavelength to generate the monitor signal.
摘要:
An optical transmission device improved in quality and reliability of OADM function and permitting configuration of highly-flexible, economical OADM networks. A wavelength tunable filter variably selects a wavelength according to a control frequency. A filter controller applies the control frequency to the filter while scanning wavelength over an entire signal bandwidth, to detect, from a reference wavelength monitor signal supplied thereto, a reference control frequency which permits the filter to select a reference wavelength and according to which wavelength is matched. On receiving a wavelength selection request, the controller obtains a target control frequency from the reference control frequency and the position of a target wavelength relative to the reference wavelength, and applies the obtained frequency to the filter. A reference wavelength filter transmits the reference wavelength therethrough. A light-receiving element monitors the transmitted reference wavelength to generate the monitor signal.
摘要:
An optical amplification apparatus includes a front-stage semiconductor optical amplifier which amplifies an input light and a rear-stage semiconductor optical amplifier which amplifies an amplified light outputted from the front-stage semiconductor optical amplifier. The front-stage semiconductor optical amplifier exercises auto level control of an output light by exercising variable control of driving current which flows according to applied voltage higher than light emitting threshold voltage of an internal optical amplification element. The rear-stage semiconductor optical amplifier performs gate switching of a transmitted light by exercising switching control of driving current. By doing so, distortion of a waveform is controlled and optical communication quality can be improved.
摘要:
A polarization controller is configured to comprise polarization state monitoring section for monitoring polarization states of input light and output light of a variable polarization light element; and a control section, when the positions on a Poincare sphere expressing each of the polarization states monitored by the polarization state monitoring section are at the positions being symmetric or approximately symmetric for the equator of the Poincare sphere, for rotating the Poincare sphere by π by using the earth axis of the Poincare sphere as a rotation axis by changing the azimuth of the optical axis of the variable polarization light element, and also for inverting the changing direction of the phase shift amount. By this, arbitrary and endless control of polarization light can be realized by a phase shift amount being less than the wavelength λ of the input light.
摘要:
A polarization controller is configured to comprise polarization state monitoring section for monitoring polarization states of input light and output light of a variable polarization light element; and a control section, when the positions on a Poincare sphere expressing each of the polarization states monitored by the polarization state monitoring section are at the positions being symmetric or approximately symmetric for the equator of the Poincare sphere, for rotating the Poincare sphere by π by using the earth axis of the Poincare sphere as a rotation axis by changing the azimuth of the optical axis of the variable polarization light element, and also for inverting the changing direction of the phase shift amount. By this, arbitrary and endless control of polarization light can be realized by a phase shift amount being less than the wavelength λ of the input light.
摘要:
The optical circuit is attachable to a ring system dedicated node apparatus, which performs add/drop on an optical signal received from a first network and transmits to a second network, so as to convert into a linear system dedicated node apparatus that performs add/drop on an optical signal received from the first or second network and transmit to the second or first network. The optical circuit includes an optical filter having a characteristic of reflecting an optical signal band supplied from the second network and transmitting an optical signal band supplied from the first network, and transmitting an occupied band of an add light in the ring system dedicated node apparatus to which the own circuit is attached at a predetermined transmission rate and reflecting the reminder. The ring system dedicated node apparatus is used in common with a part of the linear system dedicated node apparatus.
摘要:
A driving circuit of a semiconductor optical amplifier type gate switch constituting a matrix optical switch is provided with an operation amplifier into which a driving signal is input and from which a current corresponding to the driving signal is output, an inductance element provided at an output terminal of the operation amplifier, and a circuit composed of a diode element and a resistor element connected in parallel and provided between the inductance element and the semiconductor optical amplifier.
摘要:
A driving circuit of a semiconductor optical amplifier type gate switch constituting a matrix optical switch is provided with an operation amplifier into which a driving signal is input and from which a current corresponding to the driving signal is output, an inductance element provided at an output terminal of the operation amplifier, and a circuit composed of a diode element and a resistor element connected in parallel and provided between the inductance element and the semiconductor optical amplifier.
摘要:
A drive circuit is provided for a semiconductor optical amplifier type gate switch includes a first transmission path and a second transmission path. The first transmission path includes a common first sub-path between a signal source and a first node; and an individual second sub-path for each of a plurality of operational amplifiers between the first node and a corresponding one of the operational amplifiers. The second transmission path includes an individual third sub-path between each of the operational amplifiers and a second node; and a common fourth sub-path between the second node and the semiconductor optical amplifier type gate switches. Transmission delay times of all the individual second sub-paths are equal, and transmission delay times of all the individual third sub-paths are equal.
摘要:
A non-inverting amplifier circuit is disclosed that includes an operational amplifier and a preemphasis circuit connected between the operational amplifier and a signal source. The preemphasis circuit is configured to compensate for the internal delay of a load connected to the output of the operational amplifier by emphasizing a high-frequency component of a signal fed from the signal source.