Abstract

Recently we reported the observation of stimulated emission in atomic copper vapor that is excited by a resonant tunable laser beam.¹ One important result obtained in the experiment is that the two upper levels involved in the laser transitions of the atomic copper vapor are collisionally mixed in stimulated emission. This observation is particularly important for studies of high-pressure transverse-discharge copper vapor lasers. We conducted an optical pumping experiment to measure the collisional mixing cross sections (CMCSs) below the threshold of stimulated emission. We observed all four transitions: ${}^2{P}_{1/2}{-}^2{S}_{1/2}$ (327.4 nm); ${}^2{P}_{3/2}{-}^2{S}_{1/2}$ (324.8 nm); ${}^2{P}_{1/2}{-}^2{D}_{3/2}$ (578.2 nm); and ${}^2{P}_{3/2}{-}^2{D}_{5/2}$ (510.6 nm), when either one of the two levels ${}^2{P}_{3/2,1/2}$ was excited. From the measurements of the intensities of the resonantly excited and sensitized fluorescences, we estimate the CMCSs $Q_{34}\left({}^2{P}_{1/2}{\to }^2{P}_{3/2}\right)$ and $Q_{43}({}^2{P}_{1/2}\leftarrow {}^2{P}_{3/2})$ at 2 × 10⁻¹⁶ and 1.3 × 10^-16 cm² for Cu + Ne collisions, respectively. We also measured the linewidths of the optically pumped green and yellow lasers as a function of the buffer gas pressure and of detuning of the pump frequency. We observe that the linewidths change in an interesting way, which can be explained in terms of the gain narrowing.

© 1988 Optical Society of America