Laser Machining of Sub-Micrometric-Pitch Structures with a Truncated Ultrafast Bessel Beam in the Bulk of Fused Silica

Realization of photonic components made of micro and nanoscale features has paved the path towards creating photonic integrated circuits, which find application in data communication, biomedical field [1] as well as lab-on-a-chip devices [2]. The building blocks of such structures are regularly ordered arrays of nanoholes or nanochannels with a submicrometric spatial periodicity. There remain several challenges to deliver these structures featured with large lengths, controlled shape, high throughput, and larger flexibility with classical procedures like photo/electron lithography, focused ion beam and nanoimprint techniques. Moreover, these nanofabrication tools are restricted to surface processing. Therefore, albeit the spatial resolution is obviously not comparable, direct femtosecond laser ablation could find a relevant alternative to facilitate high designability in making complex structures, with unique in-volume processing abilities.