Patent application number | Description | Published |
20080205888 | Semiconductor optical amplifier type gate switch drive circuit, semiconductor optical amplifier type gate switching drive, and optical cross connect - 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. | 08-28-2008 |
20080239472 | Semiconductor optical amplification module, optical matrix switching device, and drive circuit - A semiconductor optical amplification module that can suppress ringing without increasing power consumption or circuit size or inhibiting high-speed operation. A semiconductor optical amplifier outputs an optical signal inputted according to driving current outputted from a drive circuit. A diode is connected in parallel with the semiconductor optical amplifier. As a result, it becomes possible to suppress ringing without connecting a large resistor to the drive circuit. | 10-02-2008 |
20090058534 | Non-inverting amplifier circuit and optical switch driver circuit - 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. | 03-05-2009 |
20090208227 | OPTICAL APPARATUS AND USE METHOD THEREOF FOR PASSIVE OPTICAL NETWORK SYSTEM - An optical apparatus receives an upward signal light from a plurality of subscriber units, where the upward signal light is composed of a plurality of time slots corresponding to the plurality of optical subscriber units. The optical apparatus includes a driving unit configured to determine a respective required gain for light from each of the plurality of optical subscriber units, an amplifying section configured to amplify the upward signal light with the required gain corresponding to the time slots of the upward signal light, and a receiver configured to receive the amplified upward signal light. | 08-20-2009 |
20090237127 | OPTICAL-SWITCH DRIVE CIRCUIT AND METHOD THEREOF - An optical-switch drive circuit including a driver unit that generates, in response to a control signal, an on/off signal for driving a semiconductor optical amplifier gate switch, and a buffer unit having a high input impedance and connected between an output terminal outputting the on/off signal and the semiconductor optical amplifier gate switch. In the optical-switch drive circuit the buffer unit may include a high-resistance voltage divider that is connected with the output terminal, and an operational amplifier that buffers, and provides to the semiconductor optical amplifier gate switch, a divided voltage of the voltage divider. | 09-24-2009 |
20090297147 | Drive circuit and optical switch - A drive circuit includes a first transistor that is controlled to be in on or off state in response to a control signal, and outputs, in on state, a positive current which is input from a first operational amplifier connected with a drain of the first transistor to a semiconductor optical amplifier; and a second transistor that is connected with a source of the first transistor, and is in inverse on or off state to the state of the first transistor. The drive circuit also includes a negative voltage circuit that is connected to a source of the second transistor, and outputs, when the second transistor is in on state, a negative current to the semiconductor optical amplifier. | 12-03-2009 |
20100208335 | SEMICONDUCTOR OPTICAL AMPLIFIER DEVICE - An apparatus including a semiconductor optical amplifier configured to amplify an input optical signal, and a controller configured to supply preheat current to the semiconductor optical amplifier when the input optical signal is not input to the semiconductor optical amplifier. | 08-19-2010 |
20110050293 | Driving circuit of optical gate switch - 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. | 03-03-2011 |
20110063043 | WAVEFORM SHAPING CIRCUIT AND OPTICAL SWITCHING DEVICE - A waveform shaping circuit enhances a rise of a waveform of a voltage applied to a load and includes an input unit to which the voltage is input; a supply unit configured to apply the voltage input from the input unit to the load; a first resistor connected in series between the input unit and the supply unit; a second resistor branch-connected to a portion between the input unit and the supply unit; and a stub connected to the first resistor or the second resistor and including a transmission path of a given length configured to shuttle the voltage by transmitting and reflecting the voltage as a voltage wave. | 03-17-2011 |
20110116161 | OPTICAL AMPLIFIER, CONTROL CIRCUIT, AND OPTICAL AMPLIFIER CONTROL METHOD - An optical amplifier includes a semiconductor optical amplifier, a power monitor configured to monitor an optical power of out-of-signal-band noise output from the semiconductor optical amplifier, and a corrector configured to correct a relationship between a driving current for the semiconductor optical amplifier and a noise optical power based on the out-of-signal-band noise optical power monitored by the first power monitor. | 05-19-2011 |
20110254608 | LEVEL CONTROL CIRCUIT, LEVEL CONTROL METHOD, AND LEVEL CONTROL SYSTEM - A level control circuit that generates output signal for level control includes: a control information storage that stores control information corresponding to a signal level, a control information circuit that outputs the output signal for level control corresponding to the signal level of a first input signal based on the control information stored in the control information storage; and an information update circuit that updates the control information of the control information storage according to the signal level of a second input signal. | 10-20-2011 |
20120121219 | OPTICAL-SWITCH DRIVER CIRCUIT, OPTICAL SWITCH, AND OPTICAL CHANGEOVER SWITCH - An optical-switch driver circuit includes a pulse signal source and a voltage-applying circuit. The pulse signal source generates pulse waves that rise from a first voltage to a second voltage. The voltage-applying circuit, for one of the pulse waves, outputs a voltage higher than the third voltage, then outputs a voltage lower than the third voltage, and further outputs the third voltage. | 05-17-2012 |
20120257272 | OPTICAL AMPLIFICATION APPARATUS - 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. | 10-11-2012 |