Polarization-selective Excitation of Dye Luminescence on a Gold Film by Structured Ultrashort Laser Pulses

• Published in: JETP letters 2018, Vol.107 (1), p.15-18
• Main Authors: Danilov, P. A., Saraeva, I. N., Kudryashov, S. I., Porfirev, A. P., Kuchmizhak, A. A., Zhizhchenko, A. Yu, Rudenko, A. A., Umanskaya, S. F., Zayarny, D. A., Ionin, A. A., Khonina, S. N.
• Format: Article
• Language: English
• Subjects: Atomic; Biological and Medical Physics; Biophysics; Dyes; Excitation; Excitation spectra; Femtosecond pulses; Gold; Lasers; Luminescence; Molecular; Numerical aperture; Optical and Plasma Physics; Optics and Laser Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Plasmons; Polarization; Quantum Information Technology; Rhodamine 6G; Solid State Physics; Spintronics
• ISSN: 0021-3640; 1090-6487
• DOI: 10.1134/S0021364018010034

Donut-shaped visible (515 nm) femtosecond laser pulses with linear, radial and azimuthal polarizations after tight focusing (numerical aperture NA = 0.65) have been used for spectrally adjusted excitation of plasmonenhanced rhodamine 6G dye luminescence on the surface of a nanocrystalline 45-nm thick gold film with its plasmon resonance near the laser line. Significant luminescence output increments—1.7-fold for radial polarization compared to the azimuthal one, and almost 3-fold—compared to the linear one, have been observed. This effect is related to significant transformation of the transverse electrical field component into longitudinal one for radial polarization (up to 33% in intensity, according to our calculations), and corresponding increase in excitation efficiency of plasmons in the smaller nanocrystallites throughout the film.