Probabilistic Markov Chain model of photonic crystal surface emitting lasers

Liu, Jingzhao (2026) Probabilistic Markov Chain model of photonic crystal surface emitting lasers. PhD thesis, University of Glasgow.

Abstract

Semiconductor lasers face a fundamental trade-off between high output power and high-quality single-lobe beams. Photonic crystal surface-emitting lasers (PCSELs) have emerged as a promising platform that overcomes this limitation by enabling scalable, single-mode, vertical emission. However, their design is hindered by complex interactions between microscopic scattering and macroscopic losses—especially in-plane loss (α//), which is critical yet difficult to measure experimentally.

This thesis introduces a computationally efficient Probabilistic Markov Chain (PMC) model to bridge microscopic physics and device performance. By treating light propagation as a stochastic process, the model translates coupling coefficients into directional scattering probabilities, enabling rapid simulation of finite-sized PCSELs without directly solving Maxwell’s equations.

The PMC model is quantitatively and qualitatively validated by predicting the performance (e.g. loss, slope efficiency and near-field pattern) of PCSEL devices (GaN-based PCSEL, GaAs-based PCSEL and InP-based PCSEL) from references and against experimental PCSEL and resonator-embedded PCSEL (REPCSEL) data. The predicted result has excellent agreements (e.g. < 1 cm-1 difference in loss) with those reported in references and experimental. Through parametric studies, it quantifies the impact of in-plane coupling and integrated mirrors on α// and mode control. Furthermore, the model reveals an interdependence between in-plane and internal loss in designs with unpumped boundaries, challenging conventional design assumptions. Finally, three novel high-efficiency PCSEL architectures are proposed and evaluated—incorporating butt-coupled passive sections, selective area intermixing, and dual contacts—to minimize parasitic losses and maximize power conversion efficiency.

In summary, this work establishes the PMC model as a versatile design tool that provides fundamental insight into PCSEL loss mechanisms and opens new pathways toward highperformance, scalable semiconductor lasers.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: T Technology > TA Engineering (General). Civil engineering (General); T Technology > TK Electrical engineering. Electronics Nuclear engineering
• Colleges/Schools: College of Science and Engineering > School of Engineering
• Supervisor's Name: Sweeney, Professor Stephen and Hogg, Professor Richard
• Date of Award: 2026
• Depositing User: Theses Team
• Unique ID: glathesis:2026-85932
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 May 2026 15:41
• Last Modified: 20 May 2026 11:57
• Thesis DOI: 10.5525/gla.thesis.85932
• URI: https://theses.gla.ac.uk/id/eprint/85932

Related URLs

• Article DOI
• Article DOI
• Article DOI
• Article DOI
• Conference proceeding
• Conference proceeding
• Conference proceeding
• Conference proceeding
• Conference proceeding
• Conference proceeding