Ultrafast Laser Writing with Pulse Temporal Contrast Control

Ultrafast laser nanostructuring of silica glass has been studied extensively due to the observation of new phenomena and a wide range of applications. Laser systems are altered because of the differences in the range of laser parameters such as repetition rate and pulse duration, but it remains an open question whether the parameters are the same when changing the laser system to reproduce results due to some hidden parameters like pre-pulses and pedestals [1], [2]. Here, we demonstrated that the pulse temporal contrast is significant, that is, nanopores-based modifications (type X) can be written using a crystalline gain media fs laser with a pulse contrast of 10 7 , while they cannot be produced by pulses with a nanosecond component and contrast of 10 3 from a fiber laser. On the other side, the nanograting-based modifications (type 2) with higher retardance can be imprinted with the fiber laser.