Magnetic-Field-Induced Alignment-to-Orientation Conversion in Sodium

We report a detailed investigation of excited-state alignment-to-orientation conversion in the presence of an external magnetic field. This counterintuitive phenomenon occurs under intermediate-coupling conditions. A weak, linearly polarized, cw laser beam was used to excite and align the Na 3P3/2 state in an atomic beam along the z direction. The degree of circular polarization of the resulting fluorescence was detected along the z direction as a function of magnetic-field strength. The spectrally integrated transitions originating from individual F levels of the 3S1/2 state yield a maximum circular-polarization fraction of ∼40%; integrating the circular polarization over all the allowed 3S1/2-3P3/2 transitions gives rise to an ∼8% effect. The results are predicted by the Breit formula, which is in excellent agreement with our observations

Production and Diagnosis of a Highly Spin-Polarized Na Beam

We describe optically pumping a beam of sodium atoms to \u3e96% mS and \u3e92% mS, mI state selection. (We have accurately measured the population of every mS, mI state in the optically pumped beam.) For the optical pumping both ground hyperfine states are pumped, using single-mode cw dye-laser radiation tuned to the 3S1/2–3P1/2 transition that is phase modulated in a LiTaO3 crystal to produce first-order sidebands at approximately the 1772-MHz hyperfine splitting of the ground state. The z-directed optical pumping is performed in a z-directed magnetic field of ~5 G. The state-selected atoms then move, in ~1 cm, into an ~200 G, z-directed field. The downstream probe laser beam is scanned through the 3S1/2 (mS, mI) → 3P3/2 (mS′, mI) transitions, which are spectroscopically resolved at 200 G, and the fluorescence intensities portray the residual populations in each of the eight 3S1/2 states

Optical phase-sensitive sampling for high fidelity capture of advanced, high baud-rate optical waveforms and signals

We discuss all-optical sampling techniques to capture optical waveforms with both high fidelity and time resolution. Different approaches are possible, each with associated performance - complexity trade-offs. We cover not only sampling of intensity waveforms but also complex modulation formats such as QPSK and 16-QAM and also discuss the distinctions between real time sampling and equivalent-time sampling

Optical phase-sensitive sampling for high fidelity capture of advanced, high baud-rate optical waveforms and signals

We discuss all-optical sampling techniques to capture optical waveforms with both high fidelity and time resolution. Different approaches are possible, each with associated performance - complexity trade-offs. We cover not only sampling of intensity waveforms but also complex modulation formats such as QPSK and 16-QAM and also discuss the distinctions between real time sampling and equivalent-time sampling