Direct optical measurement of sodium hyperfine structure using a cw dye laser and an atomic beam

Abstract

A cw dye laser is described which allows short-term frequency stability of 10–15 MHz. An experiment using this laser to measure the hyperfine absorption spectrum of the sodium D2 line is described. Results from this experiment are presented showing a resolution of the F = 2 → 3 and the F = 2 → 2 transitions.

Observation of the resonant Stark effect at optical frequencies

“…The results of these calculations predict a spectrum qualitatively similar to that measured above but differing in some respects. In particular the predicted ratio of the heights of the central peak to the sidebands is 2:l at resonance (Stroud 1973). Secondly, the areas under the sidebands are predicted to differ from each other appreciably for the detunings studied, whereas experimentally they appeared nearly equal when the laser was tuned to the high frequency side of the transition.…”

“…Thus it would appear that the optical Bloch equations are inadequate for this problem. Because of the importance of spontaneous emission in this problem, some of the theoretical attempts to predict the spectrum have used quantum electrodynamics (Stroud 1973). Unfortunately, because of the difficulty of the QED calculations, they have been carried out only for the initial transient regime; the long term solutions are unknown.…”

Experimental determinations of the hyperfine structure in the alkali atoms

“…This is usually obtained with the use of very well collimated atomic beams. A series of experiments has been carried out on Na in order to resolve the hfs of the D, (Hartig and Walther, 1973) and D, (HartigandWalther, 1973;Schuda et al , 1973;Lange et a/. , 1973) lines.…”

Tunable lasers

“…I n a cavity of similar disposition (figure 15), but including now four etalons and a three-prism coarse wavelength selector (Schuda et al 1973), a short-term frequency stability of 15 MHz (1 min) was achieved. The axial mode frequency tuning was accomplished in this arrangement by tilting a thick plate around Brewster's angle and thus varying the cavity length.…”

“…Mode locking of dye lasers can be achieved by either pumping with the output from a mode-locked laser or by the usual means available for any other laser system; that is, the inclusion within the cavity of a suitable saturable absorber. Passive mode locking of a flashlamp-pumped rhodamine 6G dye laser was initally performed by Schmidt and Schafer (1968). By deliberately narrowing the available gain bandwidth with the introduction of a Fabry-Perot etalon Arthurs et a1 (1971) demonstrated transform-limited pulse durations of -3 ps also in rhodamine 6G and subsequently in rhodamine B and cresylviolet (Arthurs et a1 1972).…”