Dissertation Defense

Turn-Key Stabilization and Digital Control of Scalable, N GTI Resonator Based Coherent Pulse Stacking Systems

Morteza Sheikhsofla


This thesis focuses on utilizing efficient algorithms for stabilization and optimization aspects of coherent pulse stacking amplification (CPSA) and developing a robust, scalable, and distributed digital control system with firmware and software integration for algorithms, to support the CPS application. We have presented the theoretical foundation of SPGD algorithm for phase stabilization, discussed its performance criteria, its convergence, and its stability. We have presented our software and hardware development for time-domain coherent combing stabilization (specifically, FPGA-based Control system with software/firmware development to support stabilization and optimization algorithms). A complete formulation for a GTI-Cavity-based noise measurement technique is presented. Characterization techniques have been presented to analyze stacking phase and amplitude noise in the system. Stacking sensitivity to errors in different control parameters has been analyzed. Noise measurement results using GTI cavities with different round-trip time have been presented and we have shown how effectively the staking phase noise in the system can be reduced by improving the noise performance of the mode-locked oscillator. Simulation and Experimental results for stabilizing different stacker configuration have been presented. And finally algorithmic control system along with software/hardware development for optimizing amplitudes and phases of the input burst has been implemented to increase stacking fidelity.

Sponsored by

Professor Almantas Galvanauskas