Dissertation Defense: Orkhongua Batjargal, "Novel Ultrafast Laser Systems Based on Nonlinear Conversion in Optical Fibers"

    Monday, May 2, 2022 - 3:00pm

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    Password: lasers


    Over the sixty years of their history, lasers have become an important part of the science and technology development. Today, we use lasers for internet communication, material processing, studying nature, medical surgeries and many other daily and advanced technological applications. Ultrafast laser systems are the most advanced pulsed laser systems. They exhibit high peak power that can be delivered over a very short period of time, from a few picoseconds to a few femtoseconds with a broad spectrum and coherent phase profile. As ultrafast laser technology improved, the need for a simpler, more compact and low-cost laser system grew. Ultrafast fiber lasers have been demonstrated to be an excellent candidate to fulfill the most demanding of current and emerging applications. They present the advantages of being compact and relatively low cost when compared to commercially available ultrafast solid state lasers. An all-fiber design also allows the system to be alignment free. In addition, fiber lasers have an excellent beam quality in single-mode operation and do not require active cooling at relatively high power operation. Besides all these advantages, fiber lasers exhibit certain challenges and limitations. This dissertation contributes towards filling the gaps in the development of ultrafast fiber lasers for certain applications such as deep tissue, multiphoton imaging.

    Three ultrafast fiber lasers based on nonlinear conversion in single-mode optical fibers are presented in this dissertation: 1) An all-fiber synchronously pumped dissipative soliton Raman laser based on phosphosilicate fiber that produces modelocked pulses at 1240 nm, 2) An all-fiber optical parametric oscillator based on birefringent phase matching in a polarization maintaining fiber that produces modelocked pulses at 1210 nm and 930 nm simultaneously and 3) A broadband 2 micron optical parametric amplifier seeded and pumped by an all-fiber source. The results of their experimental demonstrations, the overview of their intended applications as well as the physics behind these laser systems are explored.