Abstract: A free-space optical communication method is provided. The method includes generating, at a transmitter of a satellite, an optical frequency comb and a pump signal, modulating the optical frequency comb to generate a data signal and an idler signal that is a phase conjugate of the data signal, attenuating the pump signal, transmitting over free-space, from the satellite, a communication signal having the data signal, the idler signal and the pump signal, receiving from the satellite, at a receiver, the transmitted communication signal having the data signal, the idler signal, and the attenuated pump signal, amplifying, at a phase-sensitive amplifier, the data signal and the idler signal, and demodulating the data signal and the idler signal to extract data.

Abstract: A free-space optical communication method is provided. The method includes generating, at a transmitter of a satellite, an optical frequency comb and a pump signal, modulating the optical frequency comb to generate a data signal and an idler signal that is a phase conjugate of the data signal, attenuating the pump signal, transmitting over free-space, from the satellite, a communication signal having the data signal, the idler signal and the pump signal, receiving from the satellite, at a receiver, the transmitted communication signal having the data signal, the idler signal, and the attenuated pump signal, amplifying, at a phase-sensitive amplifier, the data signal and the idler signal, and demodulating the data signal and the idler signal to extract data.

Abstract: A free-space optical communication method is provided. An example method may include generating an optical frequency comb comprising a first tone and a second tone different from the first tone. The method may include modulating, by a first modulator of a first device, the first tone to generate a first signal comprising data. The method may include modulating, by a second modulator of the first device, the second tone to generate a second signal that is a phase conjugate of the first signal. The method may include transmitting, via free-space and to a second device, a communication signal having the first signal and the second signal.

Abstract: A free-space optical communication method is provided. An example method may include generating an optical frequency comb comprising a first tone and a second tone different from the first tone. The method may include modulating, by a first modulator of a first device, the first tone to generate a first signal comprising data. The method may include modulating, by a second modulator of the first device, the second tone to generate a second signal that is a phase conjugate of the first signal. The method may include transmitting, via free-space and to a second device, a communication signal having the first signal and the second signal.

Abstract: A free-space optical communication method is provided. The method includes generating, at a transmitter of a satellite, an optical frequency comb and a pump signal, modulating the optical frequency comb to generate a data signal and an idler signal that is a phase conjugate of the data signal, attenuating the pump signal, transmitting over free-space, from the satellite, a communication signal having the data signal, the idler signal and the pump signal, receiving from the satellite, at a receiver, the transmitted communication signal having the data signal, the idler signal, and the attenuated pump signal, amplifying, at a phase-sensitive amplifier, the data signal and the idler signal, and demodulating the data signal and the idler signal to extract data.

Abstract: A free-space optical communication method is provided. The method includes generating, at a transmitter of a satellite, an optical frequency comb and a pump signal, modulating the optical frequency comb to generate a data signal and an idler signal that is a phase conjugate of the data signal, attenuating the pump signal, transmitting over free-space, from the satellite, a communication signal having the data signal, the idler signal and the pump signal, receiving from the satellite, at a receiver, the transmitted communication signal having the data signal, the idler signal, and the attenuated pump signal, amplifying, at a phase-sensitive amplifier, the data signal and the idler signal, and demodulating the data signal and the idler signal to extract data.

Abstract: In accordance with the invention, a waveguide laser or amplifier having a peak absorption wavelength is provided with pump emitters having wavelengths deliberately offset from the peak absorption wavelength. The offset wavelengths of the emitters are chosen to enhance the thermal stability of the laser or amplifier. In one exemplary embodiment, the laser or amplifier is pumped by a bimodal distribution of emitters.

Abstract: An optical communication system which conserves electrical power is disclosed. Electrical power is conserved in the optical communication system by coupling a splitter to an optical amplifier. The optical amplifier is configured to receive optical signals as well as pump light. The splitter provides a portion of the pump light used in the optical amplifier to other devices (e.g., optical amplifiers, filters, modulators) of the optical communication system. Providing a portion of the pump light used in the optical amplifier to other devices in the optical communication systems conserves electric power by reducing the total electrical power needed to operate the optical communication system.

Abstract: In accordance with the invention, a pumped waveguide device comprising a pump waveguide and an active waveguide is provided with a pump power monitor by disposing between the pump source and the active waveguide, an indicator waveguide having a core doped with a material sensitive to the pump light. For example the material can fluoresce in response to pump light or absorb pump light and generate heat. Pump power is then accurately measured by the fluorescence or heat from the indicator waveguide. Since the fluorescence or heat is generated in the doped core, the measurement is sensitive to the pump power that will enter the active waveguide and is relatively insensitive to changes in mode distribution. Exemplary embodiments include monitored cladding pumped fiber lasers, amplifiers and light sources.

Abstract: A method and article for monitoring and controlling power drift in the output of a diode array is described. The diode array is used, for example, as a light pump for a fiber laser. In one embodiment, an improved fiber laser includes the light pump, which launches light into a laser cavity. The fiber laser further includes a sampler operable to receive at least a portion of the light before it is launched into the laser cavity. The sampled portion represents a known fraction of the total light signal generated by the light pump. In some embodiments, the sampled light is directed, via the sampler, to a photodetector. The photodetector converts the sampled light into a first electrical signal and delivers it to a processor. The processor is operable to compare the electrical signal with a set-point signal representative of a desired power output of the sampled portion of the launched light.

Abstract: The performance of optical fiber Raman devices can be increased by substitution of a broadband reflector (typically a multilayer dielectric mirror) for some of the narrowband reflectors (typically fiber Bragg gratings) that are conventionally used to define the optical cavities of the device. The device exemplarily is a Raman laser or amplifier, and in preferred embodiments a broadband reflector reflects all the Stokes-shifted wavelengths, such that the cavities are defined by the single broadband reflector and by a multiplicity of appropriately selected narrowband reflectors. Optionally the broadband reflector also serves to reflect the pump radiation.

Abstract: An optical communication system comprising a light source, a cladding pumped fiber laser having a pump cladding, an optical fiber attached to the cladding pumped fiber laser, the optical fiber having a cladding and a protective coating, and an expedient that prevents substantial damage to the protective coating of the optical fiber upon transmission of at least 1 watt of residual light out of the pump cladding.