摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Provided is a dispersion-shifted fiber for an optical parametric amplifier. The dispersion-shifted fiber is a silica-based optical fiber and has a large nonlinear coefficient and a small effective area. The dispersion-shifted fiber also reduces a bending loss and a splice loss due to a mode field diameter difference between it and a conventional single mode fiber. For this, the dispersion-shifted fiber comprises a rectangular core with a very small radius and a high refractive index, a depressed inner clad, and an outer clad with a ring. The core and/or the inner clad are/is doped with a heavy metal.
摘要:
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.
摘要:
An optical communication system and method using Manchester encoded signal remodulation are provided. The optical communication system includes a transmitter generating and transmitting a Manchester encoded optical signal including a first data stream, and a receiver receiving an optical signal obtained by dividing power of the Manchester encoded optical signal into two parts and modulating one of the two parts to include a second data stream, and recovering the second data stream. In two-way communication, the optical communication system and method allow one party to generate and transmit a Manchester encoded signal (i.e., a downstream signal) to the other party and allow the other party to generate an upstream signal by modulating the optical power of the downstream signal without using a light source.
摘要:
Provided is a dispersion-shifted fiber for an optical parametric amplifier. The dispersion-shifted fiber is a silica-based optical fiber and has a large nonlinear coefficient and a small effective area. The dispersion-shifted fiber also reduces a bending loss and a splice loss due to a mode field diameter difference between it and a conventional single mode fiber. For this, the dispersion-shifted fiber comprises a rectangular core with a very small radius and a high refractive index, a depressed inner clad, and an outer clad with a ring. The core and/or the inner clad are/is doped with a heavy metal.
摘要:
In order for a packet transporting system to transport packets for service in real time, the system estimates whether the first route for transporting the packet provides the quality of service (QoS) required by the service. If the first route is qualified to provide the QoS for transporting the packet, the system estimates whether the first route group including the first route satisfies the reliability required by the service. If the first route group is disqualified to provide the reliability required by the service, the system searches for the second route different from the first route, adds the second route to the first route group, and estimates whether the updated first route group satisfies the reliability, and if, as a result of the reliability estimation, the updated first route group is qualified to provide the reliability, transports the packet in real time by using the first route group which is comprised of the first route and the second route.
摘要:
A method and apparatus for providing a video-on-demand (VOD) service are provided. The VOD service providing method includes: receiving a media setup request message from a user terminal, converting the media setup request message using a second protocol which is different from a first protocol on which the media setup request message is based, transmitting the converted media setup request message through a transmission network, receiving a response message in response to the converted media setup request message through the transmission network, converting the response message using the first protocol on which the media setup request message is based, and transmitting the response message to the user terminal; and converting the converted media setup request message received through the transmission network using the first protocol on which the media setup request message is based, transmitting the newly converted media setup request message to a VOD streaming server, converting the response message from the VOD streaming server using the second protocol, and transmitting the converted response message through the transmission network. Therefore, by preventing overlap of control processes, which may both be initiated when two protocols are used together, it is possible to efficiently perform controlling of a VOD service.
摘要:
Provided are an acousto-optic filter and an optical code division multiple access (CDMA) system using the acousto-optic filter. The acousto-optic filter includes: an acousto-optic mode converter (AOMC) converting an optical signal of a specific optical frequency corresponding to a frequency of an electric signal of an optical signal of a first mode having a predetermined optical frequency band; and a mode stripper (MS) stripping an optical signal of the optical signal of the first mode that has been converted to a second mode.