[INVITED] Ultrafast laser micro-processing of transparent material

•Current status of the ultrafast laser micro-processing in transparent material is discussed.•Mechanism and applications of the permanent structural modifications are reviewed.•Welding techniques for glass materials are introduced with applications to hermetic sealing.

Focusing ultrafast laser pulses inside a transparent material induces localized permanent structural modifications. Using these permanent structural modifications, one can produce photonic devices and micro-channels inside the bulk of a transparent material in three-dimensions. By virtue of localized melting and resolidification in materials, joining or welding is achieved between pieces of the same or different materials. This welding technique for transparent materials using ultrafast laser pulses is also reviewed along with applications to hermetic sealing. The mechanisms and applications of ultrafast laser micro-processing in transparent material are discussed.