摘要:
A method of generating high-power laser output in the 1100 to 1500 um spectral region having a controllable linewidth. A Raman amplifier comprised of one or more nested pairs of fiber Bragg grating cavities tuned to the 1st, 2nd, . . . N−1st order Stokes wavelengths is seeded with both the desired Nth order Stokes output wavelength and the corresponding zeroth-order Stokes pump wavelength. As the pump wavelength propagates through the apparatus, it is sequentially converted to the 1st, 2nd, . . . N−1st order Stokes wavelengths in the nested fiber Bragg grating cavities. The desired Nth order Stokes output wavelength is then amplified by the N−1st Stokes order as it propagates through the nested fiber Bragg grating cavities. The linewidths of various Stokes orders can be controlled through adjusting resonant bandwidths of the fiber Bragg grating cavities by offsetting, through heating, the reflectivity bandwidths of each pair of cavity gratings.
摘要:
A method of implementing a high-power coherent laser beam combining system in which the output of a master oscillator laser having a linewidth broader than the Stimulated Brillouin Scattering linewidth of the laser signal is split into N signals and fed into an array of N optical fibers. This is a modification of the self-synchronous LOCSET and self-referenced LOCSET phase matching systems in which the optical path length of each optical fiber is matched to less than the signal coherence length of the master oscillator by using a path length matching signal processor to modulate temperature controlled segments of each optical fiber.
摘要:
A desired Nth-order Stokes output and corresponding zeroth-order Stokes pump wavelengths are seeded into a Raman amplifier comprised of one or more Raman resonators in series sequentially tuned to the 1st, 2nd, . . . N−1st Stokes orders. The pump wavelength is amplified and sequentially converted to the 1st, 2nd, . . . N−1st order Stokes wavelengths as it propagates through the apparatus. The desired Nth-order Stokes output wavelength is then amplified by the N−1st Stokes order as it propagates through the final resonator tuned to the N−1st Stokes order. Each Raman resonator includes a Raman photosensitive Raman fiber located between a pair of Bragg gratings. The linewidths of the various Stokes orders can be controlled through adjusting the resonant bandwidths of the Raman resonators by offsetting, through heating, the reflectivity bandwidths of each pair of Bragg gratings respectively located in the Raman resonators.
摘要:
A third-order Stokes signal at the desired output wavelength of 1240 nm and a zeroth-order Stokes pump wavelength at 1066 nm are seeded into a Raman amplifier comprised of two nested resonators tuned to the first-order Stokes line at 1118 nm and second-order Stokes line at 1176 nm, respectively. The pump wavelength is first amplified and then sequentially converted into the first and second-order Stokes wavelengths as the light traverses the nested resonators. The desired third-order Stokes output wavelength is then amplified by the second-order Stokes wavelength as it propagates through the outermost resonator. Each Raman resonator includes a photosensitive Raman fiber located between a pair of Bragg gratings. The linewidths of the various Stokes orders can be controlled through adjusting the resonant bandwidths of the Raman resonators by offsetting, through heating, the reflectivity bandwidths of each pair of Bragg gratings respectively located in the Raman resonators.
摘要:
A broad linewidth, zeroth Stokes order 1069 nm pump and a narrow linewidth second Stokes order 1178 nm seed propagate through a wavelength division multiplexer and then through a rare-earth-doped amplifier. After passing through a 1121 nm long period or tilted Bragg grating, the amplified 1069 nm Stokes signal and the 1178 Stokes signal are injected into a 1121 nm resonator Raman cavity, which includes a pair of highly reflective Bragg gratings having a center wavelength of 1121 nm. The amplified 1069 nm Stokes signal is Raman converted to high power levels of 1121 nm which then, in turn, amplifies the 1178 nm Stokes seed as it traverses the cavity. The linewidth of the amplified 1178 nm Stokes signal can be controlled by offsetting, through heating, the reflectivity bandwidth of the Bragg grating located near the output end of the Raman cavity.
摘要:
A coherent laser beam combining system wherein the output of a single master oscillator is split into a plurality of signals, the signals are electronically modulated at unique frequencies. One signal is designated a reference signal while the remaining signals are passed through phase adjusters. All signals are optically amplified, aligned and passed through a beam splitter to split off a small sample that is imaged onto a photodetector. The photodetector output is fed to a signal processor that produces phase error signals that drive the phase adjusters resulting in a high-powered optically coherent output signal.
摘要:
A method of full-duplex electromagnetic communication wherein a pair of data modulation formats are selected for the forward and return data links respectively such that the forward data electro-magnetic beam serves as a carrier for the return data. A method of encoding optical information is used wherein right-hand and left-hand circular polarizations are assigned to optical information to represent binary states. An application for an earth to low earth orbit optical communications system is presented which implements the full-duplex communication and circular polarization keying modulation format.
摘要:
An apparatus and method wherein polarization rotation in alkali vapors or other mediums is used for all-optical switching and digital logic and where the rate of operation is proportional to the amplitude of the pump field. High rates of speed are accomplished by Rabi flopping of the atomic states using a continuously operating monochromatic atomic beam as the pump.
摘要:
A coherent laser beam combining system wherein the output of a single master oscillator is split into a plurality of signals, the signals are electronically modulated at unique frequencies. One signal is designated a reference signal while the remaining signals are passed through phase adjusters. All signals are optically amplified, aligned and passed through a beam splitter to split off a small sample that is imaged onto a photodetector. The photodetector output is fed to a signal processor that produces phase error signals that drive the phase adjusters resulting in a high-powered optically coherent output signal.
摘要:
A coherent laser beam combining system wherein the output of a single master oscillator is split into a plurality of N signals, and the N signals are electronically modulated at unique frequencies. There is no reference signal and all of the signals are passed through phase adjusters. All N signals are optically amplified, aligned and passed through a beam splitter to split off a small sample that is imaged onto a photodetector. The photodetector output is fed to a signal processor that separates the N signals and produces N phase error signals that drive the N phase adjusters resulting in a high-powered optically coherent output signal.