Transient Dynamics and Duty-Cycle Optimization in a Pulse-Wwidth Modulation Bell--Bloom Pumping
Year: 2026
Type: preprint
Abstract: We investigate the duty-cycle-dependent atomic response under full-depth intensity pulse-width modulation in Bell--Bloom optical pumping. A time-domain Bloch model explicitly resolves the pump-on/off spin dynamics, yielding piecewise analytical transient solutions and a periodic steady-state description without cycle averaging or harmonic truncation. An extended free-induction-decay method independently determines the effective dark and pump-on transverse-relaxation rates, $W_0$ and $W$. The predicted lock-in responses agree well with experimental results. We find that for each Larmor frequency $ω_0$, the slope is maximized at a finite pump rate that increases with $ω_0$. These results provide a practical framework for sensitivity-oriented optimization of the duty cycle and pump rate in PWM-driven atomic magnetometers.
Source: arXiv (Cornell University)
Institutions: Hefei University of Technology, Anhui University
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204196677