MAT1

							               MAT-1, Ultrafast laser materials processing – micromachining of glass,
                                     semiconductors and metals

Project Leader:       R. Fedosejevs, University of Alberta
Researchers:          S. L. Chin and R. Vallée, Université Laval; Y. Y. Tsui, University of Alberta;
                      P. R. Herman and R. S. Marjoribanks, University of Toronto

Laser Micromachining is a powerful technique for defining, fabricating, and modifying materials of all types
on size scales now approaching the nanometer domain. A particular area of interest is the patterning of
dielectric materials such as glass to deliver highly integrated and compact optical circuits for Canada’s
rapidly evolving photonics industry. Waveguide structures will be written inside transparent glasses using
femtosecond laser pulses and to shallow depths using deep ultraviolet laser pulses. Precise control of the
laserinduced refractive index modifications and the laser-generated surface structures are essential for
generating Bragg grating reflectors, couplers, and interferometric devices that can eventually be
integrated into highly functional optical circuits. The laser driven mechanisms range from melting,
densification and the writing of colour centres in the glass, to ablative expulsion of material from the
surface of the glass. Another rapidly growing application area is the drilling of holes and troughs in glass
substrates for applications in microfluidic devices (lab-on-a-chip, gene assays, etc.) - components now
required by biophotonic researchers. A newly proposed technique of drilling angled intersecting holes to
allow jumpering of fluidic channels over intervening channels will be studied in detail. The drilling, rates
and morphology will be studied comparing femtosecond near infrared, nanosecond ultraviolet and
nanosecond vacuum ultraviolet laser pulses in glass and plastics. Specific aspects of melting and
recrystallization of the expelled material and debris generation will be also examined in detail.
Fundamental aspects of near threshold nanomachining and functionalising of surfaces will be studied
experimentally and via molecular dynamic simulations in order to allow for fine tuning of critical surface
dimensions in nanostructures and to engineer surface characteristics for specific applications, particularly
in biophotonics. In year 2 laser microfluidic channels and optical circuit components like waveguides and
gratings will be combined onto single bio-chip platforms to probe cells, genes and proteins.

Affiliates involved in this project:     Aurora Nanodevices, Axis Photonique, Dalsa, EXFO, Integrated
                                         Optics Communications, and Micralyne