Stephen Durbin

While x-ray science has been unsurpassed in uncovering the detailed atomic structure of materials, today’s sources are so powerful that an x-ray pulse can actually change the electronic and structural properties of a material on ultrafast time scales. We have shown how an intense x-ray synchrotron pulse absorbed by the semiconductor GaAs can drive it into an optically transparent state for laser light that would otherwise be absorbed (Durbin, S.M., et al., X-ray pump optical probe cross-correlation study of GaAs. Nature Photonics, 2012. 6(2): p. 111-114). More recent studies have successfully used x-rays to excite such a high density plasma of electron-hole pairs in GaAs that stimulated emission of band gap radiation is seen, an x-ray excited version of a semiconductor laser diode. Other investigations have uncovered unique interactions between both laser and x-ray pulses of high intensity, resulting in optical amplification, stimulated emission, energy storage in metastable defects, and isochoric heating approaching warm dense matter.