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 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.