Abstract: An antenna alignment apparatus includes a first antenna alignment unit. The first antenna alignment unit may include: a flange coupled to a transmit antenna jig providing two-axis rotational motion; a first bearing coupled to the flange; a cylinder inserted into the first bearing to rotate; an optical fiber collimator inserted into and aligned with the cylinder and having a variable focal length; an optical fiber mounted on the optical fiber collimator; and a plurality of screws contacting an external side surface of the optical fiber collimator through an external side surface of the cylinder and aligning a central axis of the optical fiber collimator and a central axis of the cylinder.

Abstract: A pulse laser output stabilizing apparatus including a directional coupler to receive output of pulse laser, the output branching into a first optical path and a second optical path, a photodetector to receive light branching into the first optical path and output current according to intensity of the light, a current-voltage converter to convert output current of the photodetector into a voltage and output converted voltage, a function generator to provide an output proportional to output signal of the current-voltage converter with a predetermined frequency, a time delay unit on the second optical path providing a predetermined time delay for feedback control, and an acousto-optic tunable modulator to receive output signal of the functional generator and optical signal from the time delay unit as an input and modulate and output the optical signal from the time delay unit according to amplitude of the output signal of the function generator.

Abstract: The present invention relates to an apparatus and a method for inspecting quantum efficiency homogeneity of a solar cell using a spatial light modulating device. The apparatus includes a light emitting device configured to radiate predetermined light; a spatial light modulating device configured to change a light path of rays emitted from the light emitting device according to individual control of a plurality of pixels; a spatial light modulating device controller configured to individually control the states of the plurality of pixels; a solar cell which the rays passing through or reflected from the spatial light modulating device irradiate; and a calculation controller configured to calculate quantum efficiency of the solar cell based on a photocurrent signal generated from the solar cell.

Abstract: The present invention relates to an apparatus and a method for inspecting quantum efficiency homogeneity of a solar cell using a spatial light modulating device. The apparatus includes a light emitting device configured to radiate predetermined light; a spatial light modulating device configured to change a light path of rays emitted from the light emitting device according to individual control of a plurality of pixels; a spatial light modulating device controller configured to individually control the states of the plurality of pixels; a solar cell which the rays passing through or reflected from the spatial light modulating device irradiate; and a calculation controller configured to calculate quantum efficiency of the solar cell based on a photocurrent signal generated from the solar cell.

Abstract: A channel allocation method of channels having different transmission speeds in a wavelength division multiplexing (WDM) system is provided. The channel allocation method in a multirate optical transmission system includes selecting a channel having the lowest transmission speed from not allotted channels, allotting the selected channel to the longest wavelength band of empty wavelength bands, and determining whether not allotted channels exist in order to repeatedly perform selecting the channel having the lowest transmission speed from the not allotted channels and allotting the selected channel to the longest wavelength band of the empty wavelength bands, until all the channels are allotted.

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: 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: A channel allocation method of channels having different transmission speeds in a wavelength division multiplexing (WDM) system is provided. The channel allocation method in a multirate optical transmission system includes selecting a channel having the lowest transmission speed from not allotted channels, allotting the selected channel to the longest wavelength band of empty wavelength bands, and determining whether not allotted channels exist in order to repeatedly perform selecting the channel having the lowest transmission speed from the not allotted channels and allotting the selected channel to the longest wavelength band of the empty wavelength bands, until all the channels are allotted.

Abstract: A multichannel fiber laser whose wavelength range is expansible to increase the number of lasing channel, and whose channel output powers are equalized, in order to provide a useful multichannel laser source having a wide bandwidth is described. The laser comprises a gain offering means; a gain equalizing means; and a resonating means. In addition, a method for designing the spectral profile of a gain equalizing filter for the purpose of this invention is described.

Abstract: An improved long wavelength-band EDFA (L-band EDFA) is disclosed. The EDFA includes an input terminal for receiving signal light, a pumping unit for pumping a 1,530 nm wavelength band pumping light, a WDM coupler for multiplexing the signal light and the pumping light, and an EDF pumped by a 1,530 nm wavelength band pumping light for amplifying the signal light. Compared with conventional 1,480 nm pumping, the EDFA pumped by 1,530 nm band pumping have about two times higher power conversion efficiency.

Abstract: An improved long wavelength-band EDFA (L-band EDFA) is disclosed. The EDFA includes an input terminal for receiving signal light, a pumping unit for pumping a 1,530 nm wavelength band pumping light, a WDM coupler for multiplexing the signal light and the pumping light, and an EDF pumped by a 1,530 nm wavelength band pumping light for amplifying the signal light. Compared with conventional 1,480 nm pumping, the EDFA pumped by 1,530 nm band pumping have about two times higher power conversion efficiency.