Physics Commons^™

Multi-Kilowatt Fiber Laser Amplifiers And Hollow-Core Delivery Fibers, Matthew Cooper

Graduate Thesis and Dissertation 2023-2024

High-power fiber lasers have emerged as a cornerstone in the realm of laser technology. Characterized by their exceptional efficiency, ruggedness, and versatility, fiber lasers are experiencing widespread use in manufacturing, medical, defense, science, and in long range sensing. Unfortunately, high-power applications require strict spatial and spectral performance characteristics to be maintained, which has yet to be perfected.

This dissertation discusses the power scaling of ytterbium-doped fiber laser amplifiers, presenting three significant advancements. First, a novel photonic lantern-based method is introduced for real-time monitoring of laser beam modal content and beam quality. Initial tests highlight the photonic lantern's efficiency in predicting …

Specialty Fiber Lasers And Novel Fiber Devices, Clemence Jollivet

Electronic Theses and Dissertations

At the Dawn of the 21st century, the field of specialty optical fibers experienced a scientific revolution with the introduction of the stack-and-draw technique, a multi-steps and advanced fiber fabrication method, which enabled the creation of well-controlled micro-structured designs. Since then, an extremely wide variety of finely tuned fiber structures have been demonstrated including novel materials and novel designs. As the complexity of the fiber design increased, highly-controlled fabrication processes became critical. To determine the ability of a novel fiber design to deliver light with properties tailored according to a specific application, several mode analysis techniques were reported, addressing the …

Peak Power Scaling Of Nanosecond Pulses In Thulium Based Fiber Lasers, Christian Gaida

Electronic Theses and Dissertations

Thulium based fiber lasers represent a promising alternative for pulse energy scaling and high peak power generation with ytterbium based systems at 1µm. Advantages of thulium arise from the operation at longer wavelengths and a large gain bandwidth (1.8-2.1µm). Nonlinear effects, such as self phase modulation, stimulated Raman scattering and stimulated Brillouin scattering generally limit peak power scaling in fiber lasers. The longer wavelength of thulium fiber lasers and large mode field areas can significantly increase the nonlinear thresholds. Compared to 1µm systems, thulium fiber lasers enable single mode guidance for two times larger mode field diameter in step index …

Power Scaling Of Large Mode Area Thulium Fiber Lasers In Various Spectral And Temporal Regimes, Timothy Mccomb

Electronic Theses and Dissertations

High power thulium fiber lasers are interesting for a myriad of applications due to their potential for high average output power, excellent beam quality, compactness, portability, high operating efficiency and broad, eye-safe spectral range from 1.8-2.1 microns. Currently, the majority of thulium laser research effort is being invested into scaling average output powers; however, such output powers are being scaled with no degree of control on laser system output spectrum or temporal behavior. Thulium fiber laser technology is not useful for many of its most important applications without implementation of techniques enabling tunable, narrow spectral widths with appropriate pulse durations …