초록 ▼

A long pulse laser system emits 500-1000 ns quasi-rectangular pulses at 527 nm with near diffraction-limited divergence and near transform-limited bandwidth. The system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) ph

A long pulse laser system emits 500-1000 ns quasi-rectangular pulses at 527 nm with near diffraction-limited divergence and near transform-limited bandwidth. The system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) phase conjugator system, and a free-running single frequency Nd:YLF master oscillator. Completely passive polarization switching provides eight amplifier gain passes. Multiple frequency output can be generated by using SBS cells having different pressures of a gaseous SBS medium or different SBS materials. This long pulse, low divergence, narrow-bandwidth, multi-frequency output laser system is ideally suited for use as an illuminator for long range speckle imaging applications. Because of its high average power and high beam quality, this system has application in any process which would benefit from a long pulse format, including material processing and medical applications.

대표청구항 ▼

An apparatus for producing a long-pulse-width, narrow-bandwidth, near diffraction limited quality output beam, comprising: means for producing a polarized low power laser beam with an exponentially rising leading edge having a time constant tt1/(dG(t)/dt)＿(Pon/EsatA); at least one optical amplifier;

An apparatus for producing a long-pulse-width, narrow-bandwidth, near diffraction limited quality output beam, comprising: means for producing a polarized low power laser beam with an exponentially rising leading edge having a time constant tt1/(dG(t)/dt)＿(Pon/EsatA); at least one optical amplifier; means for providing multiple amplification passes of said polarized low power laser beam, said multiple amplification passes propagating through said at least one optical amplifier to produce at least one amplified beam with nearly constant output power determined by said time constant of said exponentially rising leading edge of said polarized low power laser beam; means for reversing the phase of said polarized low power laser beam and its propagation direction after half of said multiple amplification passes through said at least one optical amplifier, said reversing means including stimulated-Brillouin-scattering (SBS), wherein said amplified beam retraces its path and relative polarization through said at least one optical amplifier; and means for converting said at least one amplified beam into at least one output beam by passively switching the polarization of said at least one amplified beam.