Measurement of the rubidium D2 natural transition linewidth

The Diode Pumped Alkali Laser (DPAL) is an optically-pumped three-level laser system with significant promise for scaling to high power. The rates for velocity changing collisions in the rubidium laser have been measured using sub-Doppler laser saturation spectroscopy. Spectra of the F”=2 to F’=1,2,3 hyperfine components of the Rb S1/2 – P3/2 D2 transition were observed for argon pressures of 0-110 mTorr and modulation frequencies of 700 3200 Hz. Sub-Doppler features with linewidths of about 23 MHz, or about four times the natural linewidth, were observed for the hyperfine transitions and cross-over resonances. A Doppler pedestal is also observed which increases with pressures and decreases with modulation frequency. The size of the Doppler pedestal relative to the homogeneous features yields a rate for reversing the direction of all velocity groups of 3.2 x 10 cm s.The Diode Pumped Alkali Laser (DPAL) is an optically-pumped three-level laser system with significant promise for scaling to high power. The rates for velocity changing collisions in the rubidium laser have been measured using sub-Doppler laser saturation spectroscopy. Spectra of the F”=2 to F’=1,2,3 hyperfine components of the Rb S1/2 – P3/2 D2 transition were observed for argon pressures of 0-110 mTorr and modulation frequencies of 700 3200 Hz. Sub-Doppler features with linewidths of about 23 MHz, or about four times the natural linewidth, were observed for the hyperfine transitions and cross-over resonances. A Doppler pedestal is also observed which increases with pressures and decreases with modulation frequency. The size of the Doppler pedestal relative to the homogeneous features yields a rate for reversing the direction of all velocity groups of 3.2 x 10 cm s.

AIAA Plasmadynamics and Lasers ConferenceJun 28, 20100 citations

Studies of rubidium number density and polarization using spectrally-broadened diode lasers

E T Litaker

We have made systematic studies of rubidium (Rb) number density and polarization with the purpose of comparing a variety of techniques used to make these measurements. We have used five different temperatures, 40°C to 100°C in 15° increments, to compare number density measurements made using optical absorption with those made using Faraday rotation. A diode laser operating in the region near the Rb D1 transition was used in the case of the former, while for the latter two different lasers were used, one each operating in the vicinity of the Rb D1 and D2 transitions. These number density results are compared with those obtained from vapor temperature formulae (e.g., Killian, CRC, etc.). We have also made a systematic study of Rb optical pumping using an amplified tunable diode laser which has been incrementally broadened in order to determine the effect of linewidth broadening on Rb polarization. We vary the frequency of the circularly-polarized pump laser across the D1 transition absorption profile for each of four linewidths (0.01, 0.5, 2, and 8 GHz) and measure the Rb polarization using Faraday rotation. The Rb number density for these measurements is on the order of 1012 cm−3, with 1 Torr of N2 as the buffer gas. These results are then compared with polarization measurements taken using a re-pump laser operating near the Rb D2 transition, and with theoretical calculations of the rubidium polarization.We have made systematic studies of rubidium (Rb) number density and polarization with the purpose of comparing a variety of techniques used to make these measurements. We have used five different temperatures, 40°C to 100°C in 15° increments, to compare number density measurements made using optical absorption with those made using Faraday rotation. A diode laser operating in the region near the Rb D1 transition was used in the case of the former, while for the latter two different lasers were used, one each operating in the vicinity of the Rb D1 and D2 transitions. These number density results are compared with those obtained from vapor temperature formulae (e.g., Killian, CRC, etc.). We have also made a systematic study of Rb optical pumping using an amplified tunable diode laser which has been incrementally broadened in order to determine the effect of linewidth broadening on Rb polarization. We vary the frequency of the circularly-polarized pump laser across the D1 transition absorption profile for each of four linewidths (0.01, 0.5, 2, and 8 GHz) and measure the Rb polarization using Faraday rotation. The Rb number density for these measurements is on the order of 1012 cm−3, with 1 Torr of N2 as the buffer gas. These results are then compared with polarization measurements taken using a re-pump laser operating near the Rb D2 transition, and with theoretical calculations of the rubidium polarization.

Jan 1, 20140 citations

Observation of Subnatural Linewidth in Na D2 Lines

Fujio Shimizu, Kazuko Umezu, Hiroshi Takuma

Subnatural linewidth in the optical transitions of Na ${D}_{2}$ lines was directly observed with use of phase switching of the optical field and gating of the photon counter. A linewidth as narrow as 4.5 MHz compared with the natural width of 10 MHz was obtained.Subnatural linewidth in the optical transitions of Na ${D}_{2}$ lines was directly observed with use of phase switching of the optical field and gating of the photon counter. A linewidth as narrow as 4.5 MHz compared with the natural width of 10 MHz was obtained.

Physical Review LettersSep 21, 198135 citations

Spectroscopic investigation of the rubidium resonance line

T. Rieper, T. Rose, Volkmar Helbig +1 more

AIP conference proceedingsJan 1, 19970 citations

Subnatural linewidth in the optical transitions of Na

{D}_{2}

lines was directly observed with use of phase switching of the optical field and gating of the photon counter. A linewidth as narrow as 4.5 MHz compared with the natural width of 10 MHz was obtained.