Abstract: An optical communication system includes a transmission fiber that is operable to receive at least one optical signal and at least one pump signal. The optical signal includes one or more optical signal wavelengths and a power level at approximately a minimum threshold power level. The pump signal co-propagates with at least a portion of the optical signal over at least a portion of the transmission fiber. In one particular embodiment, the pump signal operates to amplify the optical signal to approximately a maximum threshold power level as the pump signal and the optical signal traverse the portion of the transmission fiber.

Abstract: A method of communicating an optical signal includes generating an optical signal at a bit rate of at least 2.5 Gb/s. The optical signal including at least thirty optical channels. In one particular embodiment, at least some of the thirty optical channels reside within a 1567-1620 nanometer wavelength range. The method also includes receiving the optical signal at a ROPA that includes a rare-earth doped optical fiber. In addition, the method includes introducing a pump signal to a communication span of the unrepeatered optical communication system. The pump signal operable to amplify the optical signal by Raman amplification within the communication span and including at least one pump signal wavelength operable to excite the rare-earth doped fiber. The method further includes receiving the optical signal after the optical signal has traversed at least 200 kilometers of the communication span.

Abstract: An optical communication system includes a gain medium that is capable of receiving at least one optical signal that includes one or more optical signal wavelengths. The system also includes one or more pump sources that are capable of generating at least one pump signal for introduction to the gain medium. The pump signal includes one or more fractional Raman order pump wavelengths having a Raman gain peak that is a non-integer multiple of one stokes shift from each of the one or more optical signal wavelengths. In one particular embodiment, the pump signal interacts with the optical signal as the pump signal traverses at least a portion of the gain medium.

Abstract: A method of communicating an optical signal includes generating an optical signal at a bit rate of at least 2.5 Gb/s. The optical signal including at least thirty optical channels. In one particular embodiment, at least some of the thirty optical channels reside within a 1567-1620 nanometer wavelength range. The method also includes receiving the optical signal at a ROPA that includes a rare-earth doped optical fiber. In addition, the method includes introducing a pump signal to a communication span of the unrepeatered optical communication system. The pump signal operable to amplify the optical signal by Raman amplification within the communication span and including at least one pump signal wavelength operable to excite the rare-earth doped fiber. The method further includes receiving the optical signal after the optical signal has traversed at least 200 kilometers of the communication span.

Abstract: A method of communicating an optical signal includes generating an optical signal at a bit rate of at least 2.5 Gb/s. The optical signal including at least thirty optical channels. In one particular embodiment, at least some of the thirty optical channels reside within a 1567-1620 nanometer wavelength range. The method also includes receiving the optical signal at a ROPA that includes a rare-earth doped optical fiber. In addition, the method includes introducing a pump signal to a communication span of the unrepeatered optical communication system. The pump signal operable to amplify the optical signal by Raman amplification within the communication span and including at least one pump signal wavelength operable to excite the rare-earth doped fiber. The method further includes receiving the optical signal after the optical signal has traversed at least 200 kilometers of the communication span.

Abstract: An optical communication system includes a transmission fiber that is operable to receive at least one optical signal and at least one pump signal. The optical signal includes one or more optical signal wavelengths and a power level at approximately a minimum threshold power level. The pump signal co-propagates with at least a portion of the optical signal over at least a portion of the transmission fiber. In one particular embodiment, the pump signal operates to amplify the optical signal to approximately a maximum threshold power level as the pump signal and the optical signal traverse the portion of the transmission fiber.

Abstract: An optical communication system includes a gain medium that is capable of receiving at least one optical signal that includes one or more optical signal wavelengths. The system also includes one or more pump sources that are capable of generating at least one pump signal for introduction to the gain medium. The pump signal includes one or more fractional Raman order pump wavelengths having a Raman gain peak that is a non-integer multiple of one stokes shift from each of the one or more optical signal wavelengths. In one particular embodiment, the pump signal interacts with the optical signal as the pump signal traverses at least a portion of the gain medium.

Abstract: There is disclosed a mode-locked optical fiber laser stabilizing apparatus for stabilizing the length of the optical fiber laser resonator by feedbacking the optical signals to the laser resonator, in the direction where the signal reflected by the optical fiber loop mirror is detected as an error signal to minimize the signal, and method thereof.

Abstract: An apparatus for generating an optical fiber laser capable of tuning a wavelength thereof.

Abstract: A planar waveguide-type optical amplifier switch is disclosed. The switch is developed with the purpose of solving the problems that the conventional waveguide-type optical switch, which has been being used in the optical communication technique, has an optical loss and thereby requires an external optical amplifier which makes the whole devices not suitable for forming an integrated compact device. The disclosed switch performs switching function from the refractive index change in the optical waveguides induced by electrical or optical controls as well as amplifying function of the optical signal, when it passes through the waveguides, from use of optical waveguides formed of a fluorescence emitting material with an optical pumping and a wavelength division multiplexing (WDM) optical waveguide-type coupler.

Abstract: An optical fiber cascaded Raman laser scheme is provided. An optical fiber cascaded Raman laser scheme in accordance with an embodiment of the present invention includes a pump light source, an optical fiber, a wavelength division multiplexing optical fiber combiner, another wavelength division multiplexing optical fiber combiner, a short period optical fiber bragg grating, a long period bragg grating, first means, and second means. The pump light source generates pump light. The optical fiber causes Raman scattering regarding the optical pump light as nonlinear material. The wavelength division multiplexing optical fiber combiner forms intra cavity regarding light of second order stoke frequency shifted wavelength. The light is stoke frequency shifted by Raman scattering of the optical fiber. The another wavelength division multiplexing optical fiber combiner forms intra cavity regarding light of first and third order stoke frequency shifted wavelength.

Abstract: An optical fiber mode-locked laser is disclosed. The laser comprises a gain medium doped optical fiber to achieve a population inversion between high and low energy levels by a pump light source and to oscillate optical waves in sequence, a cholesteric liquid crystal circular polarization mirror to transmit the waves from the pump light source and to be operated as a circular polarization reflection mirror for the oscillated optical waves from the gain medium doped optical fiber, a polarization controller to control the polarization state of the proceeding light which is oscillated from the gain medium doped optical fiber, a dispersion shifted fiber to give a non-linear effect to the proceeding light through the polarization controller, and an optical fiber laser output mirror which forms a resonator by putting out some portion of the proceeding light by transmission and reflecting the other portion of the light.

Abstract: An optical fiber Raman laser includes an optical fiber which is a nonlinear optical medium, for implementing a nonlinear Stokes frequency shift; a wavelength-division multiplexing optical fiber coupler means, coupled to said optical fiber in parallel, for separating each Stokes frequency shifted wavelengths and pump wavelength, for internally resonating the Stokes frequency shited light wavelengths and for output-coupling said laser output light which is a second order Stokes frequency shifted wavelength; a first fiber Bragg grating means connected to said wavelength division multiplexing (WDM) optical fiber coupler means in serial, for transmitting light of the pump source and for selecting output wave of the Raman laser; and a second fiber Bragg grating means connected to said wavelength division multiplexing (WDM) optical fiber coupler means, which has maximum reflectivity on the wavelength of the pump source, for full-reflecting and re-inputting the light of the pump source to said optical fiber.