We have observed the effect of angled excitation beams on the photon echoes from the 22S1/2–22P1/2 transition of atomic lithium. The degradation of the echo from noncollinear excitations is not so great as had been feared. A calculation with the billiard-ball echo model is in good agreement with our experimental results. In a similar experiment in atomic-sodium vapor we have recorded a decay of echo intensity with increasing pulse separation over nearly 12 orders of magnitude, with the weakest signals coming from atoms that had been more than 23 lifetimes in their excited state.We have observed the effect of angled excitation beams on the photon echoes from the 22S1/2–22P1/2 transition of atomic lithium. The degradation of the echo from noncollinear excitations is not so great as had been feared. A calculation with the billiard-ball echo model is in good agreement with our experimental results. In a similar experiment in atomic-sodium vapor we have recorded a decay of echo intensity with increasing pulse separation over nearly 12 orders of magnitude, with the weakest signals coming from atoms that had been more than 23 lifetimes in their excited state.

Journal of the Optical Society of America BApr 1, 19844 citations

Continuous Spatial Photon Echoes

C. Schnurr

Jan 1, 19940 citations

Photon echoes in lithium vapor with the use of angled excitation beams

Raymond John Beach, Burton Brody, Sven R. Hartmann

Two-pulse photon echoes on the $2^{2}S_{\frac{1}{2}}\ensuremath{-}2^{2}P_{\frac{3}{2}}$ transition in lithium vapor are generated using laser excitation pulses with angular separations of 0.70 and 1.40 mrad. The observed degradation of echo intensity with angling of the excitation pulses is in agreement with theory. The largest echoes radiated by the lithium sample contained ${10}^{9}$ photons; the smallest echoes detected contained only an average of 0.04 photons. This intensity range of greater than ${10}^{10}$ represents measurements made over more than 15 natural lifetimes of the $2^{2}P_{\frac{3}{2}}$ state despite the degradation due to angling. Modulation of the echo signal due to the hyperfine structure of the $2^{2}P_{\frac{3}{2}}$ state is also observed.Two-pulse photon echoes on the $2^{2}S_{\frac{1}{2}}\ensuremath{-}2^{2}P_{\frac{3}{2}}$ transition in lithium vapor are generated using laser excitation pulses with angular separations of 0.70 and 1.40 mrad. The observed degradation of echo intensity with angling of the excitation pulses is in agreement with theory. The largest echoes radiated by the lithium sample contained ${10}^{9}$ photons; the smallest echoes detected contained only an average of 0.04 photons. This intensity range of greater than ${10}^{10}$ represents measurements made over more than 15 natural lifetimes of the $2^{2}P_{\frac{3}{2}}$ state despite the degradation due to angling. Modulation of the echo signal due to the hyperfine structure of the $2^{2}P_{\frac{3}{2}}$ state is also observed.

Physical Review AJun 1, 198316 citations

Recent Photon Echo Experiments

Norman A. Kurnit, Sven R. Hartmann

Springer eBooksJan 1, 19678 citations

{10}^{9}

photons; the smallest echoes detected contained only an average of 0.04 photons. This intensity range of greater than

{10}^{10}

represents measurements made over more than 15 natural lifetimes of the

2^{2}P_{\frac{3}{2}}

state despite the degradation due to angling. Modulation of the echo signal due to the hyperfine structure of the

2^{2}P_{\frac{3}{2}}

state is also observed.