Search results for "Selective reflection"
showing 3 items of 3 documents
Extreme increase in atomic transition probability of the Cs D_2 line in strong magnetic fields under selective reflection
2016
Selective reflection of 852-nm laser radiation from the interface between cesium vapor and the sapphire window of a 30-micrometer-thick microcell was used to record an extreme increase in the probability of the Fg=3→Fe=5 transitions associated with the Cs-atom D2 lines in magnetic fields with inductions ranging from 300 to 3200 Gauss. We showed that a group of seven transitions Fg=3, mF=−3, −2, −1, 0, +1, +2, +3→Fe=5, mF=−2, −1, 0, +1, +2, +3, +4 was formed in accordance with the selection rules ΔmF=+1 for σ+-circularly-polarized radiation. These seven transitions have much higher probabilities in 500–1000 Gauss magnetic fields, with three of the transitions having probabilities higher than…
Tuneable multicoloured patterns from photonic cross-communication between cholesteric liquid crystal droplets
2014
Monodisperse droplets of planar-aligned cholesteric (N*) liquid crystal exhibit an intriguing capacity for photonic cross-communication, giving rise to colourful patterns that depend sensitively on the N* pitch, droplet positions and illuminated area. The phenomenon results from a combination of omnidirectional selective reflection of N* droplets—which thus act as spherically symmetric self-assembled photonic crystals—and total internal reflection at the continuous phase surface. We outline how the unique optical properties can be employed in numerous applications.
Selective reflection spectroscopy of alkali vapors confined in nanocells and emerging sensing applications
2019
This thesis is aimed at studying the resonant interaction of a laser radiation with an atomic alkali vapor layer of wavelength-scale thickness confined in an optical nanocell; and emerging sensing applications.We focus our attention on the selective reflection arising at the interface between a dielectric window and a resonant alkali vapor, and show that the derivative of selective reflection spectra exhibit narrow resonances whose maxima are located exactly at atomic resonance frequencies. These resonances are observed with a spectral linewidth up to fifteen times smaller than the Doppler linewidth of the medium and their amplitudes scale linearly with respect to the transitions ones. Owin…