Abstract: A vacuum processing apparatus has a degassing chamber and does not need a large-sized vacuum evacuation device. In the process of heating and degassing an object to be processed in the degassing chamber, transferring the object to be processed into a processing chamber through a buffer chamber; and performing vacuum processing, the degassing chamber is connected to an vacuum evacuation system having a low evacuation speed and degassing processing is performed in a vacuum atmosphere of 1 to 100 Pa (time 0 to t2). Next, the object to be processed is moved to the buffer chamber, and the pressure inside the buffer chamber is lowered to near the pressure of the processing chamber (time t2 to t3), then the buffer chamber and the processing chamber are connected, and the object to be processed is transferred into the processing chamber.

Abstract: A vacuum processing apparatus has a degassing chamber and does not need a large-sized vacuum evacuation device. In the process of heating and degassing an object to be processed in the degassing chamber, transferring the object to be processed into a processing chamber through a buffer chamber; and performing vacuum processing, the degassing chamber is connected to an vacuum evacuation system having a low evacuation speed and degassing processing is performed in a vacuum atmosphere of 1 to 100 Pa (time 0 to t2). Next, the object to be processed is moved to the buffer chamber, and the pressure inside the buffer chamber is lowered to near the pressure of the processing chamber (time t2 to t3), then the buffer chamber and the processing chamber are connected, and the object to be processed is transferred into the processing chamber.

Abstract: A reliable optical transmission system with an improved signal control mechanism that avoids abrupt power variations of light beams, thereby preventing optical supervisory channel (OSC) signals from experiencing errors. An optical amplifier amplifies main signals under the control of an optical amplifier controller, which spends a first predetermined time to raise the output power of the optical amplifier up to a desired level. A pump light source produces a pump beam for injection to a fiber-optic transmission line so as to make it serve as an amplifying medium. The pump light source is controlled by a pump light source controller that spends a second predetermined time to raise the pump beam to a desired power level. This stepwise start-up process of the amplifier power and pump beam power prevents OSC signals from experiencing abrupt power variations.

Abstract: An optical terminal apparatus includes a plurality of signal light units that transmits and receives a signal light having a predetermined wavelength; at least one pumping light unit that emits a pumping light having a predetermined wavelength to perform Raman amplification for the signal light transmitted; and an optical multiplexer/demultiplexer that multiplexes/demultiplexes the signal light and the pumping light, the optical multiplexer/demultiplexer having one end connected to an optical transmission path and other end connected to the signal light units and the pumping light unit.

Abstract: Occurrence of a reception error and breakdown of a device are prevented by absorbing an optical surge that occurs at the time of an instantaneous interruption of light. Dummy light having a wavelength at which a Raman gain is obtained when the wavelength of a main signal is assumed to be the wavelength of the pump light of a Raman amplifier is combined in a combiner with the main signal, and the combined light is introduced into an optical fiber where, by exploiting the SRS effect, the energy of the optical surge occurring in the main signal is absorbed into the dummy light, thus absorbing the optical surge.

Abstract: A reliable optical transmission system with an improved signal control mechanism that avoids abrupt power variations of light beams, thereby preventing optical supervisory channel (OSC) signals from experiencing errors. An optical amplifier amplifies main signals under the control of an optical amplifier controller, which spends a first predetermined time to raise the output power of the optical amplifier up to a desired level. A pump light source produces a pump beam for injection to a fiber-optic transmission line so as to make it serve as an amplifying medium. The pump light source is controlled by a pump light source controller that spends a second predetermined time to raise the pump beam to a desired power level. This stepwise start-up process of the amplifier power and pump beam power prevents OSC signals from experiencing abrupt power variations.

Abstract: A reliable optical transmission system with an improved signal control mechanism that avoids abrupt power variations of light beams, thereby preventing optical supervisory channel (OSC) signals from experiencing errors. An optical amplifier amplifies main signals under the control of an optical amplifier controller, which spends a first predetermined time to raise the output power of the optical amplifier up to a desired level. A pump light source produces a pump beam for injection to a fiber-optic transmission line so as to make it serve as an amplifying medium. The pump light source is controlled by a pump light source controller that spends a second predetermined time to raise the pump beam to a desired power level. This stepwise start-up process of the amplifier power and pump beam power prevents OSC signals from experiencing abrupt power variations.

Abstract: An optical terminal apparatus includes a plurality of signal light units that transmits and receives a signal light having a predetermined wavelength; at least one pumping light unit that emits a pumping light having a predetermined wavelength to perform Raman amplification for the signal light transmitted; and an optical multiplexer/demultiplexer that multiplexes/demultiplexes the signal light and the pumping light, the optical multiplexer/demultiplexer having one end connected to an optical transmission path and other end connected to the signal light units and the pumping light unit.

Abstract: An optical transmission device which efficiently suppresses variations among loss levels in optical fiber transmission, and improves quality of optical transmission. A WDM port is connected to an optical transmission line, and functions as a port for transmission and reception of a wavelength-multiplexed signal. A wavelength multiplex/demultiplex unit has optical filters which are daisy-chain connected, and realize a loss characteristic weighted at respective wavelengths in correspondence with a wavelength-dependent loss characteristic of the optical transmission line. Each of the optical filters has a function of a band-pass filter and an identical insertion loss.

Abstract: A reliable optical transmission system with an improved signal control mechanism that avoids abrupt power variations of light beams, thereby preventing optical supervisory channel (OSC) signals from experiencing errors. An optical amplifier amplifies main signals under the control of an optical amplifier controller, which spends a first predetermined time to raise the output power of the optical amplifier up to a desired level. A pump light source produces a pump beam for injection to a fiber-optic transmission line so as to make it serve as an amplifying medium. The pump light source is controlled by a pump light source controller that spends a second predetermined time to raise the pump beam to a desired power level. This stepwise start-up process of the amplifier power and pump beam power prevents OSC signals from experiencing abrupt power variations.