| The BELLA laser at the Berkeley Lab, during construction. In the foreground, units of the front end stretch and amplify short, relatively weak laser pulses before further amplification in the long central chamber. Amplification is done by titanium sapphire crystals boosted by a dozen pump lasers. At the far end of the hall the now highly energetic stretched pulse is compressed before being directed to BELLA’s electron-beam accelerator component. (Photo Roy Kaltschmidt, Lawrence Berkeley National Laboratory) |
