Standard optical potentials use off-resonant laser standing wave induced AC-Stark shift. In a recent development [Phys. Rev. Lett. {\bf 117}, 233001 (2016)] three-level scheme in $\Lambda$ configuration coupled coherently by resonant fields was introduced leading to an effective lattice with subwavelength potential peaks. Here as extension of that work four level atomic setup the tripod is used...

TEMPO/NaBr/NaClO-mediated surface oxidation of NCC, acid-extracted from aspen kraft pulp, was studied, and the properties of nanocellulose whiskers before and after oxidation were characterized by conductimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and atomic force microscopy. The resulting products with varied oxidation degrees were then applied in the deinked pulp to ev...

a quantum theory of a two and three-level laser with injected atomic coherence is developed by using a density operator method, to the best of our knowledge, for the first time. the initial atomic coherence plays an essential role. at steady state, the equation of motion for the density operator yields to exhibit laser without inversion and a phase locking but no threshold for the laser field. ...