Keywords

Transparent Ceramics, Laser Materials, Direct Ink Write, Additive Manufacturing, Gain Media

Abstract

Transparent ceramics (TCs) offer a key advantage over single crystals as solid-state laser materials, in that their composition can be spatially varied to improve laser performance. In this work, additive manufacturing (AM) techniques were applied to TC fabrication to produce laser gain media with engineered gain and index profiles. We have used direct ink write (DIW) to fabricate laser rods and channel waveguides and introduced ink-spraying, a new technique, to realize multilayer planar waveguides. Modifications to the DIW process, including the use of sacrificial drying layers to promote uniform drying, the optimization of the drying, burnout and calcination steps all led to the successful scale up of AM’ed laser rods to 13 cm long and 1 cm in diameter. Using this technique, Nd3+ and Cr4+ co-doped yttrium aluminum garnet (YAG) laser rods were produced and tested in self Q-switched operation. These generated pulses of 20 to 50 nanoseconds with up to 273 mJ per pulse, the first TC self Q-switched laser of this type. The use of DIW to fabricate channel waveguides (CWGs) was also pioneered. Yb:YAG laser CWGs, with diameters as small as 50 µm, were fabricated and demonstrated a high optical-optical laser slope efficiency of 61%. Additionally, a new method of fabricating TC planar waveguides (PWGs) was developed by spraying a colloidal nanoparticle suspension on a powder bed to produce uniform, thin (< 10 µm) layers enabling the manufacture of intricate PWGs. Via ink-spraying, single and multilayer waveguides, for mode selective ribbon lasers, with total thicknesses of 40 to 69 µm were produced and lased with similar slope efficiencies, up to 31%. Through these novel processes the versatility of high optical quality AM’ed TC laser gain media has been demonstrated, paving the way for future laser gain media with improved thermal management, beam quality, compactness, and laser operation.

Completion Date

2025

Semester

Spring

Committee Chair

Gaume, Romain

Degree

Doctor of Philosophy (Ph.D.)

College

College of Engineering and Computer Science

Department

Materials Science and Engineering

Identifier

DP0029365

Document Type

Dissertation/Thesis

Campus Location

Orlando (Main) Campus

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