Quantum statistics of the gain-narrowed Raman linewidth inH2

Abstract

Recent studies have shown that single-shot spectra in stimulated Raman scattering can be much narrower than the quantum-mechanical gain-narrowed linewidth. However, shot-to-shot fluctuations in the single-shot spectra are such that the ensemble average gives the gain-narrowed linewidth. This happens because the mean frequencies of the single-shot spectra fluctuate from shot to shot under the gain-narrowed linewidth, and because some ‘‘noisy’’ shots are broadened or display multipeaked spectra. The nature of these quantum-noise-initiated fluctuations will be discussed in this paper, with both numerical and experimental results presented. Noisy, multipeaked, single-shot spectra will be shown to have a broader distribution of mean frequencies than the distribution of near-Fourier-transform-limited spectra.