Doppler-Free Laser Spectroscopy Measurements on a Ne Discharge for Determination of²²Ne-²⁰Ne Isotope Shifts

Abstract

not been measured by laser spectroscopy. For the studied lines data from a precision optical spectroscopy investigation by Odintsov [21] are available for comparison and a good We have used Doppler-free polarization spectroscopy, intermodulated fluorescence and intermodulated optogalvanic spectroscopy for measuring isotope shifts m 6 Ne lines connecting the 2ps3s and 2p53p agreement is Obtainedconfigurations. The measurements were performed on two different In the next section we describe the measurement arrangehollow cathodes. For the 5852, 5882, 5945, 5976, 6143 and 6 1 6 4 A ments used in the experiments and in Section 3 the measurelines the *zNe-20Ne isotope shift was found to be 2300(15), 1740(2), ments and results are presented. In a final discussion, different are in fair agreement with previous optical spectroscopy data.

Sub-doppler frequency measurements on OCS at 87 THz (3.4 *m) with the CO overtone Laser:

“…different experimental approaches were investigated to see which was best for making sub-Doppler measurements on the OCS transitions. The first involved saturated-absorption techniques [14][15][16][17][18]20,22,23], and the second used polarization-selective optical-heterodyne techniques [24,[28][29][30][31][32][33][34][35][36][37]40,[43][44][45][46][47].…”

“…Since then, this versatile method has been used not only for several laser spectroscopic measurements, but also for laser stabilization [38][39][40][41][42][43][44][45][46][47]. The principle of operation is that a strong pump beam introduces an anisotropy in a sample; that is, the sample becomes dichroic and birefringent if the pump frequency is near a molecular resonance.…”

“…Since both birefringence and dichroism can contribute to the signal here, the most difficult problem is to obtain a line shape that is symmetric about the true line center [37,45,46]. The local oscillator wave E can be obtained most conveniently from the probe beam itself by slightly uncrossing the analyzer with respect to the polarizer by an angle 4>.…”

“…[37]. The recommended solutions are to use a spatial filter [24,37], an intermodulation technique [46], or a phase modulation of the pump beam [43], or to shift the frequency between the pump and probe beam [47].…”