Progress in Ultrafast Intense Laser Science VIII
The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science and optical science which has been stimulated by the re
- PDF / 1,123,137 Bytes
- 31 Pages / 439.36 x 666.15 pts Page_size
- 28 Downloads / 207 Views
Ultrafast Optical Gating by Molecular Alignment Heping Zeng, Peifen Lu, Jia Liu, and Wenxue Li
Abstract Field-free alignment of gaseous molecules could function as an ultrafast polarization optical gating with periodic revivals originated from quantum wakes of the impulsively excited molecular wave packets. Recent experimental explorations have revealed some unique applications of ultrafast optical gating from pre-excited molecular rotational wave packets, such as molecular-alignment-based cross-correlation frequency-resolved optical gating (M-XFROG) for ultrashort pulse characterization, and molecular-alignment-based ultrafast optical imaging and optical buffer with revivable optical storage in molecular rotational wave packets. The M-XFROG technique employs the impulsive transient alignment of gaseous molecules as a gate function to characterize the ultrashort pulse and exhibits the advantage of no phase-matching constraint and applicability to pulses at any wavelength ranging from ultraviolet to far-infrared. Ultrashort pulse meaurements of ultraviolet pulse, supercontinuum pulse, optical parametric amplifier, and multicolored pulses were experimentally performed by using the M-XFROG technique. Ultrafast optical imaging by periodic molecular alignment was also demonstrated, involving the optical image storage in the pre-excited molecular wakes followed by periodic readout and display. For diatomic molecules in air, both raised and intagliated monochromatic images were observed with periodic revivals of aligned molecules. Ultrafast time-encoded holographic-like imaging was realized to encode the phase information of a three-demensional object in the molecular revivals. The monochromatic images could be transformed into colorful optical imaging by using a spatially chirped supercontinuum laser pulse to chromatically encode the stored images with different colors at different delays with respect to the molecular alignment revivals.
H. Zeng () P. Lu J. Liu W. Li State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China e-mail: [email protected] K. Yamanouchi et al. (eds.), Progress in Ultrafast Intense Laser Science VIII, Springer Series in Chemical Physics 103, DOI 10.1007/978-3-642-28726-8 3, © Springer-Verlag Berlin Heidelberg 2012
47
48
H. Zeng et al.
3.1 Introduction Field-free molecular alignment [1] with periodic revivals in response to quantum wakes of molecular wave packets is achieved through impulsive rotational Raman excitation by broadband ultrashort laser pulses. The periodic revivals originated from the rephasing of the pre-excited rotational wave packets provide not only field-free control on optical properties of the molecular gaseous medium but also robust methods to reveal molecular dynamics and structures for molecular physics and chemistry. So far, molecular alignment and orientation have sparked ever-growing research interest in various related fields, such as full-dimensional molecular manipulation [2], high-order harmonic generatio
Data Loading...
