Morphology-dependent resonance

H.-M. Tzcng, K. F. Wall, M. B. Long, and R. K. Chang, Laser emission from individual droplets at wavelengths corresponding to morphology-dependent resonances, Opt. Lett. 9, 499-501 (1984). 

J. B. Snow, S.-X. Qian, and R. K. Chang, Stimulated Raman scattering from individual water and ethanol droplets at morphology-dependent resonances, Opt Lett 10, 37-39 (1985). 

Morphology dependent resonances (MDR) are observed in the fluorescence of 9-amino acridine hydrochloride hydrate (9AAHH) impregnated single microparticles. These MDRs influence the radiative rate of the molecule. From the time-resolved measurement with a resolution of ns we have determined the femtosecond dephasing time of the molecule in a polymer matrix at room temperature. 

Pumping single molecules with morphology-dependent resonances [167]... 

The same effect is visible in Raman spectroscopy, causing basehne ripples and perturbation of band intensifies. In Raman spectroscopy the effect is sometimes termed morphology-dependent resonance . 

There are few methods suitable for on-line chemical analysis of aerosol particles. Raman spectroscopy offers the possibility of identifying the chemical species in aerosol particles because the spectrum is specific to the molecular. structure of the material, especially to the vibrational and rotational modes of the molecules. Raman spectra have been obtained for individual micron-sized particles placed on surfaces, levitated optically or by an eiectrodynamic balance, or by monodisperse aerosols suspended in a flowing gas. A few measurements have also been made for chemically mixed and poly disperse aerosols. The Raman spectrum of a spherical particle differs from that of the bulk material because of morphology-dependent resonances that re.su It when the Raman scattered photons undergo Mie scattering in the particle. Methods have been developed for calculating the modified spectra (McNulty el al., 1980). 

Hill, S.C. Morphology-dependent resonances. In Optical Effects Associated with Small Particles Barber, P.W., Chang, R.K., Eds. World Scientific Publications Singapore, 1988 3-61. 

D. Morrish, X. S. Gan, and M. Gu, "Morphology-dependent resonance induced by two-photon excitation in a micro-sphere trapped by a femtosecond pulsed laser," Optics Express, vol. 12, pp. 4198-4202, 2004. 

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