Optical power limiting in ensembles of colloidal Ag{sub 2}S quantum dots

Journal Article · Thu Dec 31 00:00:00 EST 2015 · Quantum Electronics (Woodbury, N.Y.)

DOI:https://doi.org/10.1070/QE2015V045N12ABEH015909· OSTI ID:22551131

Ovchinnikov, O V; Smirnov, M S; Perepelitsa, A S; Shatskikh, T S ^[1]; Shapiro, B I ^[2]

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1. Voronezh State University, Voronezh (Russian Federation)
2. M.V. Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow (Russian Federation)

The effect of power limiting for optical radiation at a wavelength of 660 nm with a pulse duration of 10 ms and operation threshold of 2.2 – 3.1 mJ cm{sup -2} is observed in ensembles of colloidal Ag{sub 2}S quantum dots (QDs). Using the z-scanning method in an open-aperture scheme it is found that the power is limited mainly due to reverse saturable absorption caused by two-photon optical transitions that involve energy levels of Ag{sub 2}S photoluminescence centres, related to structural impurity defects in colloidal Ag{sub 2}S QDs. At the same time, the z-scanning in a closed-aperture scheme demonstrates the formation of a thermal dynamic lens. (nonlinear optical phenomena)

• OSTI ID: 22551131
• Journal Information: Quantum Electronics (Woodbury, N.Y.), Vol. 45, Issue 12; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7818
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ABSORPTION
APERTURES
DEFECTS
ENERGY LEVELS
IMPURITIES
PHOTOLUMINESCENCE
PHOTONS
PULSES
QUANTUM DOTS
SILVER SULFIDES
WAVELENGTHS