Temperature and composition dependent excitonic luminescence and exciton-phonon coupling in CdSeS nanocrystals.

The yellow- and red-emitting CdSeS nanocrystals (NCs) synthesized through one-step organometallic synthesis method are uniformly assembled in polymethyl methacrylate (PMMA). A higher-energy emission band originates from band-edge excitonic state appeared at low temperature. With the Se dopant concentration increasing, the luminescent spectra of CdSeS NCs have a red-shifted emission peak and a shorter luminescent lifetime, which is attributed to the existence of trapping state caused by surface defect and Se dopant.

Evolution of fluorescence resonance energy transfer between close-packed CdSeS quantum dots under two-photon excitation.

Energy transfer (ET) processes between quantum dots (QDS) were investigated by means of steady-state and time-resolved up-conversion luminescence measurements. Two types of CdSeS QDs with different Se/S molar ratios at the similar sizes of ~4.5 nm emit green and orange up-conversion luminescence at infrared laser excitation, separately.

Hybrid optoelectronic bistability in a fiber Bragg grating by use of a tunable fiber laser.

We report the observation of hybrid optoelectronic bistability in a fiber Bragg grating (FBG) by use of an electro-optically tuned cw fiber laser in which another wavelength-matched FBG is employed to constitute a tunable resonant cavity. The potential application of such a device as a fiber-optic sensor is also discussed.