Sergey Saakyan | Searcharxiv

arXiv2026

Collision and static widths of self-broadened line shapes in optically saturated high-density atomic vapor

We study the frequency derivatives of selective reflection from high-density rubidium vapor using a hole-burning technique. Saturation dips are observed inside the self-broadened line shapes. The line self-broadening is a combination of static width and collision width. By analyzing saturation dips, we can separate power broadening and collision width. Our experimental results support the theory of inhomogeneous dipole-dipole induced broadening of transitions in a dense atomic gas, published by J. A. Leegwater and S. Mukamel [Phys. Rev. A 49 (1994) 146].

physics.atom-ph↗

arXiv2025

Modulation transfer spectroscopy of $^7$Li D1 line

We present the first implementation of modulation transfer spectroscopy (MTS) on the D$1$ line of $^7$Li, carried out in a compact heat-pipe vapor cell with cold windows. By varying the pump and probe intensities and polarization configurations, we systematically map the MTS error-signal amplitude, effective linewidth, and slope for the ground-state crossover resonance $F=1\times2\rightarrow F'=2$. We observe Rabi-induced power broadening and identify optimal conditions for laser frequency stabilization via tightly focused beams with total power below 1 mW. The lin$\perp$lin polarization configuration yields a sharp, symmetric, high-contrast error signal with a maximal slope. Our findings establish the MTS spectrum of the $^7$Li D1 line transitions as a reliable frequency reference for quantum technology and ultracold atom experiments, particularly in scenarios where frequency stabilization must be achieved with low laser optical power.

physics.atom-ph↗