Shaping ultrafast laser interaction – gateway to novel 3D photonic integrated devices

Confined ultrafast laser interactions driven with controlled beam shapes are a major opportunity today for internal three-dimensional (3D) nano-structuring of transparent materials with tailored optical and mesoscopic properties. This presentation explores the fundamental beam propagation and interaction physics for generating narrow filaments, light sheets, and non-aberrated or aberrated beams as single or multiple beamlets into glass substrates. Computer generated beam shaping with a spatial light modulator (SLM) is targeted here towards aberration-free 3D processing inside of bulk glasses, cylindrical fibers, and thin transparent films. The beam delivery can be tailored to enhance or inhibit the ultrashort nonlinear light interaction and facilitate the formation of filaments into refractive index structures or into open capillaries. A wide gamut of photonic and micro/nano-mechanical structures can then be assembled in the bulk glass, or film, or along the core waveguide of optical communication fibre. Such additive and subtractive means of nano-processing enables the fabrication of fiber core and cladding photonics and lab-in-fibre devices not previously conceived. The processes enable formation of volume gratings, optical waveguides, micro-mechanical structures, microfluidics and nano-channels that can be combined and integrated for micro-engineering of highly functional and compact micro-systems for photonics to biosensing.

References:

Rahnama, A., et al., Adv. Photonics Res., 1: 2000026. https://doi.org/10.1002/adpr.202000026 (2020)

Rahnama, A., et al., Adv. Optical Mater. 2021, 9, 2100054. https://doi.org/10.1002/adom.202100054.

Peter R. Herman earned MASc (1982) and PhD (1986) degrees studying lasers and diatomic spectroscopy in the Physics Department at the University of Toronto and followed with a post-doctoral position at the Institute of Laser Engineering in Osaka University, Japan (1987) to the study of laser-plasma physics and x-ray lasers. He joined the Department of Electrical and Computer Engineering at the University of Toronto in 1988 where he currently holds a full professor position. He directs a large and collaborative research group that develops and applies laser technology and advanced beam delivery systems to control and harvest laser interactions in new frontiers of 3-D nanofabrication.  Our mantra is: “We begin with light and we end with light devices.” To this end, Professor Herman and his research group have made several noteworthy discoveries and research developments that have influenced industry practices and found commercial applications in broad areas of laser manufacturing. Professor Herman is OSA, SPIE and IAPLE fellow, holds several patents, spun out one company (FiLaser, now part of Coherent), and has published over 300 papers in journals and conference proceedings.