Possibility of High-Resolution Double-Quantum Laser Spectroscopy in Hydrogen

Abstract

We propose experiments for observing double-quantum transitions between the $s$ levels in atomic hydrogen. The inherent resolution is considerably higher than in the single-quantum transitions normally used for optical measurements in hydrogen. We present simplified calculations of relevant double-quantum processes, and show how they might be observed in a double-resonance extension of present techniques of precision laser spectroscopy.