ORCID

0009-0009-2277-3833

Keywords

Spatial Light Modulator, Spatial Beam Shaping, Coherent Beam Combining, Off-Axis Digital Holography, Optical Frequency Comb, Genetic Algorithm.

Abstract

Programmable spatial light modulators (SLMs) built on Liquid Crystal on Silicon (LCoS) technology enable precise control of multiple degrees of freedom of light, such as amplitude, phase, frequency, polarization, and time. We demonstrate applications of SLM technology that go beyond the conventional 4-f ultrafast pulse shaping approach. By developing a dual-oscillator power amplifier (DOPA), we show that nonlinear wave interactions inside optical fibers can be managed through the spectral phase adjustment of optical frequency combs produced by non-degenerate, cascaded four-wave mixing (CFWM). Our approach utilizes a programmable spectral phase profile, which allows precise regulation of an optical comb’s spectral content. We achieve high power-spectral-density (PSD) values of around 60 dBm/nm and pump power conversion efficiencies greater than 70%, which surpasses the performance of microcomb systems. High PSD at specific wavelengths better meets the demands for multiwavelength LiDAR and remote sensing applications than traditional supercontinuum generation technology. In the final step of this work, we reveal a technique for accurate control of bandwidth through the optimization of dispersion profile parameters from β2 to β5 using a Genetic Algorithm (GA) based on self-supervised machine learning techniques. Utilizing our C-band DOPA in conjunction with the optimized SLM phase control, we achieve a figure of merit (FOM = maximum bandwidth / minimum bandwidth) of 9. Our results show that the GA-optimized phase profile can extend the CFWM bandwidth from the C-band to the O-band (1260-1360 nm) on the short wavelength side all the way to 1850 nm on the long wavelength side. This 530 nm broad comb spectrum contains 167 comb lines with 518 GHz spacing at an average power of 120 mW.

In addition, this work extends the SLM’s functionality beyond standard spatial beam shaping to produce highpower Hermite-Gaussian (HG) modes and Orbital Angular Momentum (OAM) modes, which use mode division multiplexing (MUX)/de-multiplexing(de-MUX) to improve the optical system’s channel capacity. This dissertation illustrates how wavefront synthesis techniques using SLM combine multiple laser beams into a single high-power, high-quality beam while emphasizing that ML advances digitized phase mask creation to surpass the conventional wavefront matching method.

Completion Date

2025

Semester

Spring

Committee Chair

Hudson, Darren D.

Degree

Doctor of Philosophy (Ph.D.)

College

College of Optics and Photonics

Identifier

DP0029408

Document Type

Dissertation/Thesis

Campus Location

Orlando (Main) Campus

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