Self-induced transparency on the 1.15-μm line of neon

Self-induced transparency in an absorbing neon discharge has been observed on the nonresonance transition $2s_2\mathrm{}(J=1\mathrm{})-2\mathrm{}{p}_4\mathrm{}(J=2\mathrm{})\mathrm{}$. Since linearly polarized light pulses excite two dipole moments differing by only 18%, the absorber is virtually nondegenerate and superior in simplicity to molecular absorbers. Light pulses, generated from the output of a cw single-frequency 1.15-μm He-Ne laser oscillator by a pulsed Ne laser amplifier, were transmitted through the absorber. Comparison of the oscilloscope traces of input and output pulses indicated the occurrence of pulse retardation, peak amplification, and pulse breakup. Complete pulse reshaping to the predicted hyperbolic-secant envelope has been observed. The periodicity of transmission versus pulse power, which provides direct evidence of optical nutation, is in agreement with the results of a pulse-area-pulse-energy model.