Photoinscription of optical microstructures in fused silica with few-cycle pulses

F. FURCH; D. ENGEL; T. WITTING; A. PEREZ LEJÍA; D. BIASETTI; G.A. TORCHIA; M. VRAKING; A. MERMILOD BLONDING

California

Conferencia; SPIE LASE 2020; 2020

SPIE

Direct laser writing of surface waveguides with ultrashort pulses isa crucial achievement towards all-laser manufacturing of photonic integrated circuits sensitive to their environment. In this Letter, few-cyclelaser pulses (with a sub-10 fs duration) are used to produce subsurfacewaveguides in a non-doped, non-coated fused silica substrate. The fabrication technique relies on laser-induced micro-densification below thethreshold for nanopore formation. The optical losses of the fabricatedwaveguides are governed by the optical properties of the superstrate. Wehave measured losses ranging from less than 0.1 dB/mm (air superstrate)up to 2.8 dB/mm when immersion oil is applied on top of the waveguide.