Abstract: Provided are a Raman amplifier and a Raman pumping method. A light source unit outputs a pumping light having a wavelength that periodically changes. A light intensity control unit varies a light intensity of the pumping light using the pumping light to improve the gain flatness of a Raman gain. A control unit directs the light intensity control unit to control the light intensity of the pumping light in synchronization with changes in the wavelength of the pumping light.

Abstract: An electronic apparatus having a load including: a power supply unit supplying a driving voltage to the load; an inverter unit switching the driving voltage; and a control voltage supply unit outputting a first control voltage lower than a reference voltage applied to one terminal of the inverter unit, and a second control voltage higher than the reference voltage, thus controlling the inverter unit. Thus, the electronic apparatus and power circuit are capable of improving a control voltage applied to an inverter unit to reduce the switching loss of the inverter unit.

Abstract: A dispersion compensating fiber (DCF), which is an amplification medium of an S-band discrete Raman amplifier (RA), has a trapezoid core, an inner cladding surrounding the trapezoid core; and an outer cladding surrounding the inner cladding. A ring is disposed between the inner cladding and the outer cladding. The refractive index plotted across the diameter of the trapezoid core as a function of distance is substantially trapezoidal in shape. The difference in refractive index between the trapezoid core and the outer cladding is 1.2 to 1.6%; between the inner cladding and the outer cladding is 0.4 to 0.8%; and between the ring and the outer cladding is 0.2 to 0.6%. The thickness of the ring is 0.8 to 1.2 times the radius of the trapezoid core, and the thickness of the inner cladding is 1 to 3 times the radius of the trapezoid core.

Abstract: Provided is an erbium-doped fiber amplifier reducing transient phenomena of a signal-to-noise ratio and a bit error rate in a dynamic wavelength division multiplexing system and an amplifying method using the erbium-doped fiber amplifier. The erbium-doped fiber amplifier includes: a polarization scrambler modulating a polarization state of an input signal to remove a polarization of the input signal; an amplifier amplifying the input signal from which the polarization has been removed; a detector reading powers of input and output signals of the amplifier; and an automatic gain controller controlling currents of the pump LDs according to the powers of the input and output signals read by the detector 1630 to maintain the gain even if the power of input signal changes.

Abstract: A method for realizing, in a fiber amplifier with three stages of amplifiers, automatic gain control in which a constant gain is obtained when channels are varied, and automatic level control in which a constant output per channel is obtained when a light power is varied because of variations in span loss. A light power or another light power of a specific wavelength is monitored to determine when variations in these light powers take place, current values of pump laser diodes appropriate for an input is read from a lookup table, and pump laser diodes are driven. During this operation, a pump power of the first stage amplifier is constantly maintained, and those of the second or third stage amplifier are controlled.

Abstract: The present invention provides an apparatus and method for compensating for the variation of a gain spectrum attributable to the temperature variation of a fiber amplifier, and a long-wavelength band dispersion-compensating hybrid amplifier equipped with the gain spectrum compensating apparatus. The apparatus includes a DCF located between a first amplification stage and a second amplification stage to compensate for dispersion of an optical signal output from the first amplification stage and perform Raman amplification of the optical signal using input pumping light; at least one pumping light provision means for providing forward or backward pumping light to the DCF; first and second temperature detection means for detecting temperature variations of the first and second amplification stages, respectively; and control means for controlling intensity of the pumping light of the pumping light provision means according to the detected temperature variations.

Abstract: Disclosed is a device for metallizing uranium oxide and recovering uranium, which reacts uranium oxide with a lithium metal to product uranium metal powder, and filters the resulting product using a porous filter to separate the uranium metal powder from lithium chloride molten liquid to recover the uranium metal powder. The device includes a heating furnace including at least one first heating unit, and a reactor includes a reaction vessel having a discharging valve hole located at the center of a bottom thereof and a conical bottom tapered to the discharging valve hole, a sealing lid for sealing the reaction vessel airtight, an argon gas inlet port for feeding argon gas into the reactor therethrough, and an argon gas outlet port for venting argon gas from the reactor therethrough. A valve assembly controls the discharging valve hole of the reaction vessel, and a plurality of agitators mix a mixture in the reactor.

Abstract: Provided are a Raman amplifier and a Raman pumping method. A light source unit outputs a pumping light having a wavelength that periodically changes. A light intensity control unit varies a light intensity of the pumping light using the pumping light to improve the gain flatness of a Raman gain. A control unit directs the light intensity control unit to control the light intensity of the pumping light in synchronization with changes in the wavelength of the pumping light.

Abstract: Optical fiber amplifier with wide input power dynamic range is employed to make a first gain block and an optical fiber pumped by Raman pump have opposite spectral gain profiles each other, thereby obtaining flat output gain profile. The optical fiber amplifier includes: a first and a second gain blocks, wherein each gain block has a gain medium and at least one optical pump; an optical fiber disposed between the first and the second gain blocks; a Raman pump for generating a pumping light; and a coupling means for coupling the pumping light to the optical fiber.

Abstract: Disclosed is a device for metallizing uranium oxide and recovering uranium, which reacts uranium oxide with a lithium metal to product uranium metal powder, and filters the resulting product using a porous filter to separate the uranium metal powder from lithium chloride molten liquid to recover the uranium metal powder. The device includes a heating furnace including at least one first heating unit, and a reactor includes a reaction vessel having a discharging valve hole located at the center of a bottom thereof and a conical bottom tapered to the discharging valve hole, a sealing lid for sealing the reaction vessel airtight, an argon gas inlet port for feeding argon gas into the reactor therethrough, and an argon gas outlet port for venting argon gas from the reactor therethrough. A valve assembly controls the discharging valve hole of the reaction vessel, and a plurality of agitators mix a mixture in the reactor.

Abstract: A method for realizing, in a fiber amplifier with three stages of amplifiers, automatic gain control in which a constant gain is obtained when channels are varied, and automatic level control in which a constant output per channel is obtained when a light power is varied because of variations in span loss. A light power or another light power of a specific wavelength is monitored to determine when variations in these light powers take place, current values of pump laser diodes appropriate for an input is read from a lookup table, and pump laser diodes are driven. During this operation, a pump power of the first stage amplifier is constantly maintained, and those of the second or third stage amplifier are controlled.