dc.creator Tanaka, Takehiko en_US dc.creator Field, R. W. en_US dc.creator Harris, David O. en_US dc.date.accessioned 2006-06-15T17:09:30Z dc.date.available 2006-06-15T17:09:30Z dc.date.issued 1974 en_US dc.identifier 1974-FA-6 en_US dc.identifier.uri http://hdl.handle.net/1811/16224 dc.description This work was supported, in part, by the National Science Foundation Grant No. GP-35672X. en_US dc.description Author Institution: Quantum Institute, University of California en_US dc.description.abstract A single frequency, cw, rhodamine 6G dye laser pumps one of four optical transitions of $NO_{2}$ near 593.6 nm which have been assigned by Tanaka, et al. [j. Chem. Phys. \underline{59}, 5217 (1973)] by excitation spectroscopy and ground state MODR. The upper levels of these optical transitions are 9$_{09}$, J = 17/2 and 19/2, and $8_{18}$, J = 15/2 and 17/2 which belong to an as yet unassigned vibrational level of the $^{2}B_{2}$ electronic state. Microwave transitions originating from the optically populated excited levels are detected as changes (0.5 – 7\%) in the photoluminescence intensity monitored through a short wavelength cut off filter. Various spin and hyperfine components of the $9_{09} - 8_{18}$ rotational transition within the $NO_{2}$ $^{2}B_{2}$ electronic state are observed and assigned. Hyperfine splittings In the $^{2}B_{2}$ state are of the same order of magnitude as in the ground state. The MODR signal for $9_{9}$ - $8_{18}$ transitions has an unusual pressure dependence. If the $9_{09}$ level is optically pumped, the HOPR signal is an increase of photoluminescence near 1 mTorr, but is a decrease near 10 mTorr. However, if the $8_{18}$ level is pumped, the MODR signal always corresponds to an increase of photoluminescence. In addition to $9_{09} - 8_{18}$ transitions, mystery” microwave transitions are observed from $9_{09}$ or $8_{18}$ levels to unknown levels which belong to another vibronic state. Mystery transitions are observed as n decrease in photoluminescence intensity. Pressure dependent MODR effects and mystery transitions are explained by an electronic perturbation which affects the $8_{18}$ level more strongly than $9_{09}$. en_US dc.format.extent 285155 bytes dc.format.mimetype image/jpeg dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title MICROWAVE OPTICAL DOUBLE RESONANCE OF $NO_{2}$ WITH A CW DYE LASER. EXCITED STATE MICROWAVE TRANSITIONS en_US dc.type article en_US
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