Abstract
We report on the optical properties of volume Bragg gratings in chloride photo-thermo-refractive glass after femtosecond laser bleaching. We show experimentally that irradiation of the gratings with femtosecond laser pulses can expand their transmission into the whole visible range without dramatic decrease of diffraction efficiency. The mechanism of glass bleaching is considered and modulation of refractive index is described in terms of the coupled wave theory for mixed volume Bragg gratings.
Highlights
We report on the optical properties of volume Bragg gratings in chloride photo-thermorefractive glass after femtosecond laser bleaching
The mechanism of glass bleaching is considered and modulation of refractive index is described in terms of the coupled wave theory for mixed volume Bragg gratings
Small size of the crystalline phase in combination with absence of absorption in the visible region boosts the performance of such gratings at the small periods
Summary
It has been shown that this glass open a way to fabricate the volume mix type Bragg gratings, which possess both refractive index and absorption coefficient modulation. Additional advantage of this type of material is a small in comparison with the classic PTR glass - size of the crystalline phase that suppresses scattering and improves performance of the gratings with a period smaller than 400 nm [12]. The diffraction efficiency of such mixed gratings is limited in agreement with the coupled wave theory [13].
Sign-in/Register to view highlights & summary 
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call