Grant: Research Tools and Instruments - Category 1 (<$150,000)

Funds are requested for purchasing a high repetition rate and high energy femtosecond pulsed laser. Contrary to lasers with long pulse durations, the energy in femtosecond laser pulses can be deposited in the material before any relaxation process has time to take place. The result is an extremely high energy density in the material that can lead to unique laser-matter interaction phenomena. These phenomena will be studied and utilized for a wide range of applications. Indeed, the high energy densities produced can lead to the direct vaporization of the material without melting and thus without a significant heat-affected zone. The lack of a heat-affected zone makes femtosecond lasers ideal for micromachining. Materials with unique mechanical properties can thus be generated by extracting a miniature sample out of the bulk of materials in a controlled manner. Isolating local mechanical properties is a key element in our effort towards predicting the deformation and fracture of various classes of materials including metals, polymers and biomaterials such as bone or dentine. Because minimal heat is transferred to the material during the vaporization induced by femtosecond laser pulses, it will also be possible to machine reactive materials that would otherwise react using conventional machining techniques. High repetition rate femtosecond lasers will also be instrumental in producing photonic devices, such as lenses with complex three-dimensional shapes, and diffractive optical elements, which are difficult to produce using other techniques. Another advantage of femtosecond lasers is that they allow machining in the bulk of transparent materials. This effect will be used to machine artificial blood micro-channels in three-dimensions in the bulk of glasses and polymers for studies on blood micro-fluidics. The femtosecond laser also has a unique role in other bio-engineering applications, such as bio-imaging (live cells and tissues) and micro-surgery (eye surgery). Its use will also be instrumental for improving the bio-compatibility of metallic implants by irradiating the implant surfaces in order to control their surface topology at both nano and micro-scales.