Three-dimensional recording by tightly focused femtosecondpulses in Li Nb O 3

The authors report on a three-dimensional single-shot optical recording by 150 fs pulses at 800 nm wavelength in Fe doped Li Nb O 3 . The rewritable bits ( 2 x × 2 y × 8 z μ m 3 ) are demonstrated. The highest refractive index modulation of ∼ 10 − 3 per single pulse has been formed by preferential photovoltaic effect at close to the dielectric breakdown irradiance of ∼ TW ∕ cm 2 and was independent of polarization (in respect to the c axis). The achievable refractive index modulation is evaluated and the recording mechanisms are discussed.