Though soft glass such as tellurite or chalcogenide glass is transparent in the range of 3-6 μm, fiber made of it is difficult to generate supercontinuum (SC) to that range because of the high loss, the wavelength limit of pump source, and the challenges in 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 influence 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 long. Such a long pump wavelength ensures a large energy ratio of the glass’s bandgap to the incident photon, so the disadvantage of small bandgap of tellurite glass is reduced, and the twophoton absorption is avoided as well. We have shown that under suitable pump condition, the SC generation by filamentation can cover from visible to 6 μm. It is the broadest SC generation by tellurite (including glass and fiber). For the suitable pump condition, the glass was free of optical breakdown. If the interface reflections 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.