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Full-Text Articles in Physics
Stimulated Brillouin Scattering Phase Conjugation In Fiber Optic Waveguides, Steven M. Massey
Stimulated Brillouin Scattering Phase Conjugation In Fiber Optic Waveguides, Steven M. Massey
Theses and Dissertations
The objective of this research effort was to demonstrate the path to continuous wave, coherent beam combination through stimulated Brillouin scattering phase conjugation in optical fiber. This work experimentally determined the fiber parameters necessary for phase conjugation in step-index optical fiber. Continuous wave phase conjugation using stimulated Brillouin scattering in step-index fibers was achieved for the first time with a fidelity of 0.8 and a threshold power of 16 W in a 15-m fiber with 0.13 NA. A fidelity of 0.8 was also achieved using 40 m of fiber with 0.06-NA and a threshold power of 15 W. The fidelity …
Modeling Of Sbs Phase Conjugation In Multimode Step Index Fibers, Justin B. Spring
Modeling Of Sbs Phase Conjugation In Multimode Step Index Fibers, Justin B. Spring
Theses and Dissertations
Stimulated Brillouin scattering in a multimode step-index fiber can be used to generate a counter-propagating, phase-conjugate beam that would prove useful in many applications, such as near diffraction limited, double-pass high-power amplifiers or coherent beam combination. Relatively little modeling of such a fiber-based phase conjugator has been done, making design decisions regarding type and length of fiber largely guesswork. A numerical model was constructed with the aim of providing educated predictions about the phase conjugate fidelity that could be expected from a given pump intensity input coupled into a specific fiber. A numerical perturbation algorithm was constructed to search for …
Stimulated Brillouin Scattering Beam Cleanup And Beam Phasing Through Two Passive Channels, Omar Gamboa
Stimulated Brillouin Scattering Beam Cleanup And Beam Phasing Through Two Passive Channels, Omar Gamboa
Theses and Dissertations
Stimulated Brillouin scattering (SBS) beam cleanup and SBS piston correction properties are explored. This research measures the beam cleaning and phase-conjugating properties of stimulated Brillouin scattering in an optical fiber. The first stage of this research began by coupling an aberrated beam into a long multimode 62.5 micron core fiber to demonstrate its beam cleanup properties. The Stokes beam obtained was shown to be the fundamental fiber mode, LP01. The second stage spatially divided the pump beam into two equal halves. Each half was then sent through two different channels. The path length of one channel remained fixed while the …
Passive Multiple Beam Combination In Optical Fibers Via Stimulated Brillouin Scattering, Kirk C. Brown
Passive Multiple Beam Combination In Optical Fibers Via Stimulated Brillouin Scattering, Kirk C. Brown
Theses and Dissertations
Many active methods of scaling laser brightness have been demonstrated in recent years. The goal of this research was to demonstrate the feasibility of passively combining multiple laser beams using Stimulated Brillouin Scattering (SBS) in a long multimode optical fiber. This method of combination employed a “Gatling gun” fiber array that allowed several collimated beams to be focused by a lens into an optical fiber. The retroreflected Stokes beam is passed through the center of the beam combiner for analysis. In addition to experimental methodology and equipment used, the theoretical and historical background of SBS in optical fibers is provided. …
Multiple Channel Laser Beam Combination And Phasing Using Stimulated Brillouin Scattering In Optical Fibers, Brent W. Grime
Multiple Channel Laser Beam Combination And Phasing Using Stimulated Brillouin Scattering In Optical Fibers, Brent W. Grime
Theses and Dissertations
Brightness scaling lasers using stimulated Brillouin scattering (SBS) in optical fibers is explored. A multiple-channel amplifier approach is used to increase the total power of a laser system while avoiding a significant burden on a single channel. The work explores two approaches utilizing both SBS beam cleanup and SBS piston error conjugation. A unique beam combiner that takes advantage of the SBS beam cleanup properties of a long, gradient-index multimode fiber was designed and tested. The beam combiner was developed to combine multiple-channel laser beams simultaneously with high input and output coupling efficiency. The design for the SBS beam combiner …
Investigation Of Laser Beam Combining And Cleanup Via Seeded Stimulated Brillouin Scattering In Multimode Optical Fibers, Bryan J. Choi
Investigation Of Laser Beam Combining And Cleanup Via Seeded Stimulated Brillouin Scattering In Multimode Optical Fibers, Bryan J. Choi
Theses and Dissertations
The purpose of this thesis research was to determine if stimulated Brillouin scattering amplification in multimode optical fibers would exhibit the same laser beam combining and clean-up properties exhibited by SBS oscillation, and to characterize the Brillouin amplification process in a multimode optical fiber. Beam combining in multimode fibers via SBS is being considered as a method of combining low power laser beams into a single beam having higher power and superior spatial coherence for applications such as electro-optic countermeasures. Experimental results demonstrate seeding a 9.5 mm fiber significantly reduced the pump power required to initiate SBS. An amplified Stokes …