Luminescent molecules near metal surfaces can have dramatically decreased quantum efficiencies and lifetimes. For example, decreases of \ensuremath{\sim}${10}^{3}$ in quantum efficiency and in lifetime occur for nitrogen atoms within 3 nm of potassium surfaces. This paper presents experimental decay curves for light emission from nitrogen atoms in a ${\mathrm{N}}_{2}$ matrix of varying thickness (3 to 1000 nm) on sapphire, silver, and potassium substrates. Theoretical decay curves are derived and found to be in agreement with the experimental curves. Both experiment and theory agree that for potassium there is near-resonant coupling between excited nitrogen atoms and potassium surface plasmons. For metal films, both film thickness and surface roughness affect the decay curves.

The effects of an oxidant on the optical properties of particles formed in an inert gas containing Na vapor are reported. The oxidant used was NO. Light scattering measurements are reported. (AIP).

Quantitative laser fluorescence measurements of the concentrations of SH, S2, SO, SO2 and OH have been made in the post flame gases of a series of 10 atmospheric pressure, stoichiometric and fuel-rich H2/O2/N2 flames, containing 0, 0.25, 0.5 or 1% mole fraction of sulfur as H2S. The present discussion characterizes the chemistry of sulfur in the fuel-rich flames and also validates this fluorescence monitoring technique. A kinetic rate analysis of all the possible interactions has established that the sulfur chemistry is controlled by 8 fast bimolecular radical reactions. S, S2, SH, H2S, SO and SO2 are all coupled by fast reactions and it is only a result of the imposition of the non-equilibrated H2/O2 flame chemistry that controls their relative proportions. Termolecular reactions, other than providing a catalytic means for recombining excess H and OH concentrations are insignificant. The establishment of the equilibration of the reaction H+SO2=SO+OH provides a new method whereby fluorescence measurements of OH along with SO and SO2 can be used to determine both H and H2 concentrations in stoichiometric flames containing sulfur. This study constitutes the first systematic application of quantitative laser fluorescence measurements to a study of chemistry in a series of flames of varying composition and temperature. It demonstrates an important and powerful new method of great sensitivity and non-perturbing nature for the detailed study of combustion processes.

Laser emission, attributed to Bi2 molecules, has been observed between 650 and 710 nm, the region of Bi2 A—X emission. Bismuth vapor was optically pumped, using a flashlamp pumped dye laser, in the AX absorption bands between 540 and 580 nm. A 0.2% efficiency of this laser was found.

After gold particles are deposited onto an oxidized aluminum strip by the evaporation of gold in argon, tunnel junctions can be formed by making contact to the particles with a thin gold film. Red polarized light is emitted from these junctions when a few volts of potential difference is applied. Such junctions can be operated and stored at room temperature for several weeks.

Photon yields, chemiluminescence, and excitation spectra of gas phase reactions of atomic copper with F2, NF3, and SF6 have been obtained between 400 and 1000 nm. Distributions of excited state populations of the products of these reactions and vibrational constants of four previously unreported bands of CuF were measured. A pulsed tunable dye laser was used for excitation of CuF produced in chemical reactions or by thermal dissociation of CuF2. Analysis of rotationally resolved excitation spectra gives a new value of Bo=0.3692cm−1 for the B 1Σ state of CuF. Radiative lifetimes of 7.3 μsec for the A state, 1.2 μsec for the B state, and 0.6 μsec for the C state have been measured through an exponential fit to decays of photoluminescence following laser pulses. Additionally a lifetime of 0.2 to 2 msec for the upper state of the red system has been estimated from relative intensity measurements of the four states observed in chemiluminescence.

High resolution (0.09 eV) UPS spectra have been obtained of condensed films of N 2 and CO. All spectral features are broadened by ≳ 0.6 eV upon condensation. The origin of this broadening is discussed. The difference in linewidths for all equivalent levels, Δε CON 2 ∼ 0.1 to 0.2 eV can be understood in terms of a hole-dipole multiphonon excitation mechanism. Photoemission from what is believed o be the a 3 Π excited neutral state of CO has been detected in the solid phase for the first time.

A study has been made of emission spectra of TiO in chemiluminescent flames produced by reactions of titanium atoms with O2, N2O, NO2, NO, and CO2. Examination of the differences in intensity distributions of the Ti + N2O and Ti + O2 flames supports a recent experiment placing the a1Δ state at about 3500 cm−1 above the X3Δ ground state (1). An infrared system at 843.2 nm has been assigned as the ϵ(E3Π-X3Δ) system, which previously has been seen in an inert gas matrix (2). E3Π state constants (in cm−1) obtained from measured gas-phase bandheads were found to be T00 = 11 899.311 885.611 870.6 ± 5.0, ωe = 924.2 ± 4.5, and ωexe = 5.1 ± 1.0 Addition of active nitrogen to the flames was found to cause considerable enhancement of TiO emission.