Abstract: It is necessary to reduce the power consumption of a plurality of optical amplifiers when there is a difference in the required pumping power between the plurality of optical amplifiers; therefore, an optical amplifying apparatus according to an exemplary aspect of the invention includes a plurality of optical amplifying means for amplifying a plurality of optical signals, each of the plurality of optical amplifying means including a gain medium; a plurality of laser light generating means for generating a plurality of laser beams; at least one optical coupling means for coupling the plurality of laser beams variably in accordance with a coupling factor and outputting a plurality of excitation light beams, each of the plurality of excitation light beams exciting the gain medium; and controlling means for controlling the coupling factor and an output power of each of the plurality of laser light generating means.

Abstract: In optical amplifiers that use a multicore optical fiber, the absorption efficiency of excitation light in an optical amplification medium is low and the amplification efficiency of light intensity becomes lower in the cladding excitation method; therefore, an optical amplification apparatus according to the present invention includes an optical amplification medium, having a gain in a wavelength band of signal light, configured to receive the signal light; excitation light introduction means for introducing, into the optical amplification medium, excitation light to excite the optical amplification medium; and residual excitation light introduction means for introducing, into the optical amplification medium, residual excitation light output from the optical amplification medium, the residual excitation light having a wavelength component of the excitation light.

Abstract: A pumping light source outputs pumping lights. A pumping light source outputs a pumping light. Optical multiplexers couple the pumping lights to a plurality of cores. The optical multiplexer couples the pumping light to the clad. A pumping light source drive unit drives a pumping light source. A pumping light source drive unit drives a pumping light source. A monitoring unit outputs a monitoring signal indicating a monitoring result of the number of wavelengths used in each of optical signals amplified by the plurality of the cores. The control unit controls the power of the pumping lights based on the monitoring signal. The control unit controls the power of each of the pumping lights in accordance with the number of wavelengths used in each of the optical signals and controls the power of the pumping light so that signal qualities of the optical signals fall within a prescribed range.

Abstract: It is difficult to flatten the gain profile of an optical amplifier without increasing the power consumption, the cost, and the size of the optical amplifier; therefore, a monitoring apparatus for optical amplifier according to an exemplary aspect of the invention includes an optical filtering means for receiving a monitor light beam of the optical amplifier and transmitting a filtered monitor light beam with a set range of wavelength band; a photoelectric conversion means for converting the filtered monitor light beam into a monitoring signal; and a spectrum information generating means for generating spectrum information based on the monitoring signal, the spectrum information including information on a spectrum profile of output of the optical amplifier.

Abstract: An object is to provide an optical amplifier capable of performing Raman amplification while suppressing power consumption and a size. A multicore fiber has a double clad structure. The double clad structure includes a plurality of cores thorough which an optical signal is transmitted and a clad includes the cores. A light source outputs a pump light used for amplifying the optical signal by stimulated Raman scattering in the multicore fiber. The pump light is generated by multiplexing multimode laser lights. A optical coupler couples the pump light into the clad of the multicore fiber.

Abstract: Provided are a low-cost and low power-consumption optical fiber amplifier, an optical fiber amplifier control method, and a transmission system. The optical fiber amplifier comprises: an optical fiber to which pumping light is supplied and which amplifies an optical signal, the optical fiber including a plurality of cores in a cladding; a light source which outputs the pumping light; a combining means which supplies the pumping light from the light source to the cladding of the optical fiber and causes the pumping light to be combined with the optical signal; a collect means which collects, without collecting the signal light, pumping light among the supplied pumping light that has not been absorbed by the optical fiber; a monitor means which monitors residual pumping light that has passed through the optical fiber and collected by the collect means; and a control means which controls the state of the pumping light.

Abstract: To solve the problem that the power consumption of optical amplifiers is not optimized over the life time of an amplifier, the optical amplifier includes a gain medium for amplifying a plurality of optical channels, the gain medium including a plurality of cores through which the plurality of optical channels to propagate respectively and a cladding area surrounding the plurality of cores, a monitor that monitors the temperature of the optical amplifier and producing a monitoring result, a first light source that emits a first light beam to excite the cladding area, a second light source that emits a plurality of second light beams to excite each of the plurality of cores individually, and a controller that controls the first light source and the second light source based on the produced monitoring result.

Abstract: A discharge lamp lighting device having a discharge lamp which has a pair of tungsten-made electrodes each having a protrusion formed at the tip thereof and an electric power feeding device which feeds an alternate current electric power to the discharge lamp, and is characterized in that the power feeding device has a function of switching between a first lighting mode in which a rated electric power is fed to the discharge lamp and a second lighting mode in which a lower electric power than the rated electric power is fed to the discharge lamp to light the discharge lamp, and therefore, can control electric power to be fed to the discharge lamp under such conditions that the average electric power change rate becomes 0.01-2.1 W/s during a mode switching period in which the switching from the first lighting mode into the second lighting mode is carried out.

Abstract: A cross-sectional area calculation section calculates a cross-sectional area of a subject as physical quantity with respect to a size of the subject, and an NEC calculation section calculates a noise equivalent count NEC as physical quantity for evaluating an image. The C-NEC calculation section calculates a noise equivalent count per unit area C-NEC as physical quantity for evaluating an image as per size of the subject in accordance with the cross-sectional area of the subject calculated in the cross-sectional area calculation section and the noise equivalent count NEC calculated in the NEC calculation section. Accordingly, the noise equivalent count per unit area C-NEC is calculated as noted above, whereby an index may be determined that is independent of the cross-sectional area of the subject in evaluating the image.

Abstract: A discharge lamp lighting device having a discharge lamp which has a pair of tungsten-made electrodes each having a protrusion formed at the tip thereof and an electric power feeding device which feeds an alternate current electric power to the discharge lamp, and is characterized in that the power feeding device has a function of switching between a first lighting mode in which a rated electric power is fed to the discharge lamp and a second lighting mode in which a lower electric power than the rated electric power is fed to the discharge lamp to light the discharge lamp, and therefore, can control electric power to be fed to the discharge lamp under such conditions that the average electric power change rate becomes 0.01-2.1 W/s during a mode switching period in which the switching from the first lighting mode into the second lighting mode is carried out.

Abstract: A cross-sectional area calculation section calculates a cross-sectional area of a subject as physical quantity with respect to a size of the subject, and an NEC calculation section calculates a noise equivalent count NEC as physical quantity for evaluating an image. The C-NEC calculation section calculates a noise equivalent count per unit area C-NEC as physical quantity for evaluating an image as per size of the subject in accordance with the cross-sectional area of the subject calculated in the cross-sectional area calculation section and the noise equivalent count NEC calculated in the NEC calculation section. Accordingly, the noise equivalent count per unit area C-NEC is calculated as noted above, whereby an index may be determined that is independent of the cross-sectional area of the subject in evaluating the image.

Abstract: An ultra-high pressure mercury lamp in which the tungsten comprising the electrodes is prevented from spraying during starting and operation, and blackening on the inside wall of the arc tube is prevented is achieved in that at least one of the electrodes has an axial part which is made essentially of tungsten and a starting part which is made essentially of tungsten, at least one of the axial part and of the starting part containing an electron emission material with a smaller work function than tungsten such that the value of S/A in mm2/% by weight is in the range 1?S/A?1×104, S in mm2 designating the surface area of the part of the electrode projecting into the arc tube containing the electron emission material and A in % by weight indicating the concentration of the electron emission material in this part.

Abstract: An ultra-high pressure mercury lamp in which the tungsten comprising the electrodes is prevented from spraying during starting and operation, and blackening on the inside wall of the arc tube is prevented is achieved in that at least one of the electrodes has an axial part which is made essentially of tungsten and a starting part which is made essentially of tungsten, at least one of the axial part and of the starting part containing an electron emission material with a smaller work function than tungsten such that the value of S/A in mm2/% by weight is in the range 1?S/A?×104, S in mm2 designating the surface area of the part of the electrode projecting into the arc tube containing the electron emission material and A in % by weight indicating the concentration of the electron emission material in this part.

Abstract: A low pressure discharge lamp in which, even during uninterrupted operation, a low lamp voltage characteristic is maintained over a long time interval and in which high radiant efficiency can be obtained over a long time is achieved via a low pressure discharge lamp which has a tubular glass bulb in which a pair of electrodes are located opposite one another, by an electron emission material which contains lithium being included on or in the electrode substrate. Advantageously, the electron emission material contains at least one of the following materials: metallic lithium, an alloy of lithium and another metal, an oxide of lithium, a mixture of an oxide of lithium with another metal oxide, and an oxide which contains lithium and another metal element and which is a compound identified by the formula Li--M--O.sub.x where M designates at least one element selected from among the alkali earth metals, rare earth metals and transition metal, and x is the number of oxygen atoms required for valency equalization.

Abstract: A disc player comprising a signal pickup unit to read information from a disc on which program information including address information is recorded, the signal pickup unit being movable with respect to the disc, pickup drive means to drive the pickup unit for movement with respect to the disc, and a control circuit including an address memory for storing the newest one of the addresses read from the disc, a counter operative to count addresses at predetermined time intervals for producing a signal representative of an expected address indicative of the position to which the pickup unit is expected to move in the next, the expected address being updated at predetermined time intervals, a detector circuit to produce a signal each time a discrepancy is found to exist between the newest address and the expected address.

Abstract: An automatic disc player including a housing, disc carrier means to convey a disc between predetermined playback position and a predetermined withdrawal position ready to be withdrawn out of the housing upon termination of plaback operation, signal generating means for producing control signals to be predominant over various steps of the playback operation, and an electric control circuit responsive to the control signals to control the various steps of the playback operation, the signal generating means comprising position detecting means responsive to movement of the disc to the withdrawal position and operative to produce a signal when the disc being moved away from the playback position reaches the withdrawal position, and playback re-start switch means which is operative to produce a signal in response to slight movement of the disc from the withdrawal position toward the playback position, the control signals to be produced by the signal generating means including signals to control the start of playbac

Abstract: A system for playing back information recorded on a recording disc includes a first servo control system responsive to a tracking error signal, which adjusts the position of an information reading point of a pickup relative to the recording track on the recording disc, and a second servo control system responsive to a synchronizing signal contained in the playback information signal, which adjusts the speed of rotation of the recording disc.

Abstract: In a three-beam type optical data disk player, beam output disturbances due to an external disturbance such as vibration and the beam output disturbances due to a local defect on the disk are distinguished from each other, and the servo gain is adjusted according to whether the beam output disturbance is due to the external disturbance or due to the local defect, so that the main beam is controlled to correctly follow the track at all times.

Abstract: An automatic disc player including a housing, disc carrier means to convey a disc between predetermined playback position and a predetermined withdrawal position ready to be withdrawn out of the housing upon termination of playback operation, signal generating means for producing control signals to be predominant over various steps of the playback operation, and an electric control circuit responsive to the control signals to control the various steps of the playback operation, the signal generating means comprising position detecting means responsive to movement of the disc to the withdrawal position and operative to produce a signal when the disc being moved away from the playback position reaches the withdrawal position, and playback re-start switch means which is operative to produce a signal in response to slight movement of the disc from the withdrawal position toward the playback position, the control signals to be produced by the signal generating means including signals to control the start of playba

Abstract: Tracking servo control system for an information read-out system such as a video disc player system or a compact disc player system, comprises a servo loop switch for opening and closing the tracking servo loop, and a timing control circuit for generating a timing signal for controlling the servo loop switch in accordance with an on-track signal generated from a pickup output signal and zero cross timings of the tracking error signal. In order to control the operation of the servo loop switch, very accurately, a phase shift circuit is provided between a tracking signal generating means and a zero cross detection means, which has substantially the same phase characteristics as that of an equalizer circuit utilized in the tracking servo loop.