Ultrafast manipulation of hard x-rays

Photoacoustic effects may lead to the development of new devices, that directly modulate the intensity of an impinging x-ray pulse. An example is the so-called PicoSwitch, a photo-acoustic gate that allows for shortening an incident x-ray pulse to a duration of few picoseconds. The device is based on the generation and the interference of propagating strain waves in a photoexcited layer. In addition to pulse shortening, the structure can be employed as pulse diagnostic tool and arrival time monitor for optical pump - x-ray probe experiments.

Impinging (black) and reflected (red) x-ray pulse from an ultrafast x-ray switch. The device can be used for pulse diagnostics and as an arrival-time monitor in pump-probe experiments.