Filamentation and supercontinuum generation in tellurite glass

Abstract

ABSTRACT Though soft glass such as tellurite or chalcogenide glass is transparent in the range of 3 - PILEHUP DGHRILWLVGL IILFXOWto generate supercontinuum (SC) to that range because of the high loss, the wavelength limit of pump source, and the challenges i n light -coupling. To circumvent these problems, we developed SC light source by using tellurite bulk glass through filamentation. For this scheme, the optical path length in the glass is very short due to the adopted high pump power, so the negative influe nce of material loss is reduced greatly. The light -coupling is straightforward, and the coupling efficiency is high. The bulk glass for SC generation is cheap, and can be fabricated easily. We adopted a pump wavelength of 1600 nm which is comparatively lon g. Such a long pump wavelength ensures a large energy ratio of the JODVV¶VEDQGJDSWRWKHLQFLGHQWSKRWRQVRWKHGLVDGYDQWDJHRIVPDOOEDQGJDSRIWHOOXULWHJODVVLVUHGXFHGDQGWKHWZR -photon absorption is avoided as well. We have shown that under suitab le pump condition, the SC generation by ILODPHQWDWLRQFDQFRYHUIURPYLVLEOHWR P,WLVWKHEURDGHVW6&JHQHUDWLRQE\WHOOXULWH LQFOXGLQJJODVVDQGILEHU )RUthe suitable pump condition, the glass was free of optical breakdown. If the interface refl ections were deducted, the SC conversion efficiency was 87%. The SC conversion efficiency was stable. To the best of our knowledge, this is the first report on filamentation in tellurite glass which has a comparatively small bandgap. Keywords: tellurite g lass, filamentation, supercontinuum generation