[19p-231B-1~9] 4.7 Laser Material Processing and Manipulation

▲ [19p-231B-5] [INVITED] Direct Laser Writing with a Sub-Nanosecond Burst of Femtosecond Pulses Exploiting Excitation of a Deformation Wave

〇Andrey G. Okhrimchuk^1,2, Sergey S. Fedotov¹, Peter G. Kazansky³ (1.MUCTR, Russia, 2.FORC of RAS, Russia, 3.ORC, Univ. of Southampton, UK)

Keywords:direct laser writing, deformation wave, burst of femtosecond pulses

Efficient direct laser writing by means of a sub-nanosecond and a nanosecond burst of femtosecond pulses is reported. It was found that a single burst of few pulses having time separation in the range 10-3000 ps produces increased refractive index change in fused silica and sapphire. Modification enhancement with the pulse separation increase in the burst was observed on the tens picoseconds scale. It is proposed that accumulated transient tensile strain in the excitation region plays a crucial role in modification by a sub-nanosecond burst.