Abstract: This invention provides a wavelength converter and an optical cross-connect system using the same. The inventive system enables one multi-wavelength light source to provide each wavelength converter with the necessary tuned wavelength, without using individual light sources with different wavelengths for each wavelength of a multiplexer. The wavelength converter converts the input multi-channel optical signals into wavelengths used for a subsequent transmission. A wavelength division multiplexer is provided to divide all input optical signals connected to the output link into wavelength units, or collects the divided wavelength-unit optical signals. Meanwhile, a multi-wavelength light source generates a multi-wavelength optical signal, which is applied to and de-multiplexed by the wavelength division multiplexer, and then adapted as a tuned wavelength for wavelength conversion of each channel optical signal.

Abstract: An optical fiber amplifier is disclosed for amplifying an input optical signal in the long wavelength band. The amplifier include first and second pumping light sources, a photo detector for detecting the intensity of the input optical signal, an erbium-doped optical fiber, and a controller. The optical fiber is brought to a first-pumped state by the first pumping light output from the first pumping light source. This generates an amplified spontaneous emission in the short wavelength band. The optical fiber is brought to a second-pumped state by the amplified spontaneous emission and outputs an induced emission light in the long wavelength band. The second pumping light source outputs a second pumping light in the same wavelength band as the amplified spontaneous emission, while controlling the intensity of the second pumping light by an output control signal, thereby controlling the intensity of the second-pumped state of the optical fiber.

Abstract: A device for suppressing the transient effect of an optical fiber amplifier in a WDM system includes an input sensor which converts an input optical signal to an electrical signal; a transient effect suppresser for holding the electrical signal received from the input sensor for a predetermined time and for outputting the delayed signal in the form of pulses that are proportional to the variation of the number of channels; a voltage comparator for comparing the predetermined reference voltages with the amplitude of the pulses received from the transient effect suppresser and for outputting a trigger signal when the channel number is changed; a pump laser diode driver for supplying a driving voltage to a pump laser diode in response to the received pump indication signal; and, a controller for outputting the pump indication signal corresponding to the changed channel number in response to the trigger signal.

Abstract: A device for suppressing the transient effect of an optical fiber amplifier in a WDM system includes an input sensor which converts an input optical signal to an electrical signal; a transient effect suppresser for holding the electrical signal received from the input sensor for a predetermined time and for outputting the delayed signal in the form of pulses that are proportional to the variation of the number of channels; a voltage comparator for comparing the predetermined reference voltages with the amplitude of the pulses received from the transient effect suppresser and for outputting a trigger signal when the channel number is changed; a pump laser diode driver for supplying a driving voltage to a pump laser diode in response to the received pump indication signal; and, a controller for outputting the pump indication signal corresponding to the changed channel number in response to the trigger signal.