We theoretically investigate high-order harmonic generation (HHG) in the chirped inhomogeneous field. The results show that by using a chirped pulse, the HHG in the inhomogeneous field can be efficiently controlled. The harmonic cutoffs can be extended. Supercontinua with photon energies ranging from 201 to 263 eV and isolated attosecond pulses with durations less than 90 as are produced without carrier–envelope phase stabilization. Furthermore, it is shown that our scheme is robust against the variation of the inhomogeneity of the laser field. All our results are well explained by the quantum and classical analysis.

We investigate the influence of the time-dependent on-axis phase matching on broadband extreme ultraviolet (XUV) supercontinuum generation with an intense laser field. By using the strong-field approximation model and solving Maxwell’s equations we show that time-dependent on-axis phase matching can lead to broadening of the XUV supercontinuum. Moreover, we also demonstrate that the bandwidth of the XUV supercontinuum can be controlled by adjusting the beam waist of the laser field and the position of the gas medium.

We propose a scheme to generate isolated attosecond pulse using a linearly chirped two-color laser field, which includes a fundamental laser field and a weak infrared control laser field in the multicycle regime. The fundamental laser field consists of one linearly up-chirped and one linearly down-chirped pulses. The control pulse is chirped free. We compare the attosecond pulse generated in the chirped two-color field and the chirp-free field. It is found that an IAP can be generated even without carrier envelop phase stabilization in the chirped two-color laser field with a duration of 40 fs. We also discuss the influence of the relative intensity, relative phase, time delay, and chirping parameters on the generation of IAPs.

The forster resonance energy transfer (FRET) between different CdTe QDs and RhB were investigated by steady-state and femtosecond time-resolved photoluminescence spectra technique. Through the measurements on three different CdTe sample solutions, it was found that the FRET efficiency is proportional to the spectral overlap degree of CdTe QDs' emission and RhB's absorption. And the FRET efficiency was found to increase with the increase of the RhB's concentration, while the concentration increase to more than 4.5×10-5 mol/L, the transfer efficiency decreases. The FRET efficiency can reach to 32.6% when RhB concentration is 4.5×10-5 mol/L. With the wide use of FRET in biomolecular interaction analysis and cell physiology, the CdTe QDs-RhB hybrid systems could be a promising candidate for fluorescent probe and photodynamic therapy.