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.