17 research outputs found
Mode-locked diode-pumped vanadate lasers operated with PbS quantum dots
The use of glasses doped with PbS nanocrystals as intracavity saturable absorbers for passive Q-switching and mode locking of c-cut Nd:Gd0.7Y0.3VO4, Nd:YVO4, and Nd:GdVO4 lasers is investigated. Q-switching yields pulses as short as 35 ns with an average output power of 435mW at a repetition rate of 6-12 kHz at a pump power of 5-6W. Mode locking through a combination of PbS nanocrystals and a Kerr lens results in 1.4 ps long pulses with an average output power of 255 mW at a repetition rate of 100 MH
Anomalously low Rayleigh scattering by CdS/CdSe doped glasses
International audienceLight scattering (Raman, Rayleigh and Mandelshtam-Brillouin) and absorption of commercial color glasses (cut-off optical filters containing nanocrystals of ternary compounds CdSxSe1-x) were studied. It was found for the first time that the contribution of nanocrystals to the Rayleigh scattering is unprecedentedly low for some of these glasses. This conclusion is confirmed by estimation of nanocrystal size and volume fraction from low-frequency Raman scattering and absorbance spectroscopy for a chosen set of samples. Anomalously low Rayleigh scattering of nanocrystals is explained in terms of interference of light scattered by different nanocrystals (in-terparticle interference). The possibility of interparticle interference effects in the case of small volume fraction of nanocrystals is illustrated by computer simulation using the model of diffusion-limited phase transformation proposed earlier
Compact passively Q-switched diode-pumped Tm:KY(WO4)2 laser with 8 ns/30 μJ pulses
A compact diode-pumped solid-state Tm:KY(WO4)2 laser with cavity length of 1 cm passively Q-switched with a PbS-quantum-dot-based saturable absorber is presented. The laser operates at the wavelength of 1.94 ¹m and produces pulses with duration of 8 ns and energy of 30 ¹J at the repetition rate up to 4.2 kHz. The maximum output power of 120 mW is achieved at incident pump power of 1.15 W
Compact passively Q-switched diode-pumped Tm:KY(WO4)2 laser with 8 ns/30 μJ pulses
A compact diode-pumped solid-state Tm:KY(WO4)2 laser with cavity length of 1 cm passively Q-switched with a PbS-quantum-dot-based saturable absorber is presented. The laser operates at the wavelength of 1.94 ¹m and produces pulses with duration of 8 ns and energy of 30 ¹J at the repetition rate up to 4.2 kHz. The maximum output power of 120 mW is achieved at incident pump power of 1.15
Polarized emission of CdSe nanocrystals in magnetic field: the role of phonon-assisted recombination of the dark exciton
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