Slow and fast light is an important fascinating phenomenon in quantum optics. Here, we theoretically study how to achieve the ultraslow ultrafast a passive-active optomechanical system, based on ideal optomechanically induced transparency (OMIT). Under conditions of OMIT, abnormal (inverted) window will emerge accompanied with very steep dispersion, resulting that can be easily achieved at by a...

Future bandwidth demand in optical communication and signal processing systems will soon exceed 100 Gb s−1 as is commonly forecasted from a throughput experience curve for communication systems. However, such systems cannot be realized without introducing ultrafast, all-optical devices, since existing optoelectronic and electronic devices and integrated circuits would not be able to function at...

An ultrafast x-ray detector system is under development at Lawrence Berkeley National Laboratory (LBNL) for application primarily to study of ultrafast magnetization dynamics. The system consists of a fs laser, an x-ray streak camera and an elliptically polarization undulator (EPU) beamline. Polarized x-rays from an EPU can be used to measure x-ray magnetic circular dichroism (XMCD) of a sample...

Understanding space charge effects is central for the development of high-brightness ultrafast electron diffraction and microscopy techniques for imaging material transformation with atomic scale detail at the fs to ps timescales. We present methods and results for direct ultrafast photoelectron beam characterization employing a shadow projection imaging technique to investigate the generation ...

The laser-induced ultrafast demagnetization of CoFeB/MgO/CoFeB magnetic tunneling junction is exploited by time-resolved magneto-optical Kerr effect (TRMOKE) for both the parallel state (P state) and the antiparallel state (AP state) of the magnetizations between two magnetic layers. It was observed that the demagnetization time is shorter and the magnitude of demagnetization is larger in the A...

Ultrafast hierarchical OTDM/WDM network is proposed for the future core-network. We review its enabling technologies: Cand L-wavelength-band generation, OTDM-WDM mutual multiplexing format conversions, and ultrafast OTDM wavelengthband conversions.

Ultrafast laser techniques have opened up a tremendous research opportunity in studying the interaction of short pulses of light with matter. With discovering of the picosecond photoconducting hertzian dipoles and high-brightness THz beams characterized with an ultrafast detector, we have seen more and more applications of ultrafast light in noninvasive imaging. Standard methods, when applied t...

Ultrafast imaging using plane or diverging waves has recently enabled new ultrasound imaging modes with improved sensitivity and very high frame rates. Some of these new imaging modalities include shear wave elastography, ultrafast Doppler, ultrafast contrast-enhanced imaging and functional ultrasound imaging. Even though ultrafast imaging already encounters clinical success, increasing even mo...

Electron microscopy is arguably the most powerful tool for spatial imaging of structures. As such, 2D and 3D microscopies provide static structures with subnanometer and increasingly with angstrom-scale spatial resolution. Here we report the development of 4D ultrafast electron microscopy, whose capability imparts another dimension to imaging in general and to dynamics in particular. We demonst...

Optical control of spin is of central importance in the research of ultrafast spintronic devices utilizing spin dynamics at short time scales. Recently developed optical approaches such as ultrafast demagnetization, spin-transfer and spin-orbit torques open new pathways to manipulate spin through its interaction with photon, orbit, charge or phonon. However, these processes are limited by eithe...