Efficient volume Bragg gratings in various transparent materials induced by femtosecond laser pulses

Abstract

We present the realisation of volume Bragg gratings (VBGs) in different transparent non-photosensitive glasses by using femtosecond laser pulses to enable the monolithic integration of VBGs in various optical setups

Femtosecond laser pulse written Volume Bragg Gratings

“…Those cause the grating to support several spectral components. Up to now we measured up to the 27th reflection order of a VBG [4]. While extending the range of applied materials from fused silica to various other we could achieve different homogeneous refractive index modulation contrasts ranging from a few 10 −4 (e.g.…”

Experimental wavelength-multiplexed entanglement-based quantum cryptography

“…The working principle of VHGs [31] is based on diffracting elements consisting of a periodic phase or absorption perturbation which allows for narrow wavelength-selective narrowband filtering based on the Bragg phase-matching condition. The VHGs used in the experiment reflect a spectral width with a full width at half maximum (FWHM) of 0.12 nm (55 GHz) (at Alice's site) and 0.24 nm (110 GHz) (at Bob's site) of the total 4.7 nm (2.15 THz) single-photon spectrum (see figure 3(a)).…”