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A practical guide to feedback control for Pound-Drever-Hall laser linewidth narrowing

Quantum Physics 2025-08-25 v2 Atomic Physics Optics

Abstract

The Pound-Drever-Hall (PDH) technique for laser linewidth narrowing is widely used by AMO experimentalists. However, achieving a high-performance PDH locking requires substantial engineering experience, which is scattered across literature and often lacks a cohesive control-theory perspective. Excellent pedagogical papers exist on the theory of the PDH error signal but they rarely cover feedback control. General-purpose control theory literature seldom discuss PDH laser locking specifically. Although excellent PDH review articles provide thorough knowledge and practice on both aspects but they are not reader-friendly. We extend prior works by addressing component choice and loop tuning using modern tools like a vector network analyzer. We organize multifaceted engineering considerations systematically, grounded in feedback control principles. Our target reader is researchers setting up a PDH laser lock for the first time; we eschew advanced topics like minimizing residual amplitude modulation (RAM). Our guidance is illustrated by step-by-step optimization of the lock for a 1650 nm ECDL.

Cite

@article{arxiv.2412.04635,
  title  = {A practical guide to feedback control for Pound-Drever-Hall laser linewidth narrowing},
  author = {Wance Wang and Sarthak Subhankar and Joseph W. Britton},
  journal= {arXiv preprint arXiv:2412.04635},
  year   = {2025}
}

Comments

15 pages, 10 figures

R2 v1 2026-06-28T20:24:56.979Z