Annual Meeting Optical Society of America
Collisional excitation transfer in optically pumped atomic copper vapor
Nackchin Sung, Jin J. Kim
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: 2P1/2−2S1/2 (327.4 nm); 2P3/2−2S1/2 (324.8 nm); 2P1/2−2D3/2 (578.2 nm); and 2P3/2−2D5/2 (510.6 nm), when either one of the two levels 2P3/2,1/2 was excited. From the measurements of the intensities of the resonantly excited and sensitized fluorescences, we estimate the CMCSs Q34(2P1/2→2P3/2) and Q43(2P1/2←2P3/2) 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.