Highly efficient white light generation from barium fluoride

We demonstrate highly efficient white light generation by focusing 45 fs long pulses of 800 nm laser radiation with 1 mJ energy onto a 10 cm long barium fluoride crystal. The entire wavelength band from 400-1000 nm was generated with efficiency greater than 40%. We also observe multiphoton absorption induced fluorescence in the crystal. By employing line focusing geometry at low intensity, we show that white light fringes are formed with a single laser beam, indicative of the coherent property of the white light that is produced.