Graduation Semester and Year
Summer 2025
Document Type
Thesis
Degree Name
Master of Science in Electrical Engineering
Department
Electrical Engineering
First Advisor
Michael Vasilyev
Abstract
Stimulated Brillouin scattering (SBS) presents a fundamental challenge in the practical use of highly nonlinear fibers (HNLFs) for optical parametric amplifiers (OPAs), especially in systems requiring broad bandwidth and high spectral purity. Traditional SBS suppression techniques, such as pump phase dithering, can mitigate this nonlinear effect but often compromise the phase quality of the idler wave, making them unsuitable for coherent or phase-sensitive applications. This thesis introduces an alternative approach that suppresses SBS while preserving critical dispersion characteristics of the fiber by combining both structural and thermal optimization strategies.
The proposed method involves constructing a five-segment, 250-meter hybrid HNLF composed of two distinct fiber types: dispersion-decreasing (DD) and dispersion-flattened (DF) fibers. Each segment is selected based on its unique zero-dispersion wavelength (ZDW) and SBS frequency and is individually temperature-tuned to achieve uniform ZDW alignment and broadened, detuned SBS gain spectra. This combination minimizes SBS accumulation while maintaining favorable phase-matching conditions along the fiber.
Experimental results demonstrate a 5.8 dB enhancement in the product of the SBS threshold and fiber length and an improvement of more than 10 dB in the SBS-limited internal wavelength conversion efficiency compared to the reference configurations with no SBS suppression. Notably, the hybrid HNLF enables positive conversion efficiency (+0.9 dB) in a continuous-wave-pumped OPA without the need for pump modulation techniques. These findings indicate the potential of temperature-controlled, multi-segment HNLFs as a scalable and robust solution for high-performance optical parametric devices for use in advanced fiber-optic communication and signal processing systems.
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Rabbani, Hamed, "Temperature-Tuned Multi-Segment Hybrid HNLF for Enhanced SBS Suppression and Broadband Parametric Amplification" (2025). Electrical Engineering Theses. 395.
https://mavmatrix.uta.edu/electricaleng_theses/395