Towards low-loss lightwave circuits for non-classical optics at 800 and 1,550 nm

We review the recent advances in integrated quantum optical technologies, with specific emphasis on the femtosecond laser direct-write technique. We present a comparative study of the processing windows which produce low-loss waveguides in two glasses, Schott AF-45 and Corning Eagle-2000. We report the losses at wavelengths 800 and 1,550 nm, the two most critical wavelengths for quantum information science. We find the iron absorption in Eagle-2000 to be the limiting factor for propagation losses, suggesting that low Fe₂₊ glasses are better suited for quantum optical science.