Dissertation Defense: Femtosecond Laser Processing of Chalcogenide Glasses for Optofluidics
CREOL 102 November 5, 2009
10:30 AM - 12:30 PM
Announcing the Final Examination of Troy Anderson for the degree of Doctor of Philosophy in Optics.
Femtosecond Laser Processing (FLP) is a powerful and flexible processing technique that can be used to fabricate various functional elements in transparent media such as optical waveguides, diffractive optical elements, and hollow micro-channels. Bypassing linear absorption and exploiting nonlinear absorption of the laser light, FLP is capable of sub-surface modification and enables the fabrication of 3D device geometries not easily obtained using other methods. Optofluidics, the integration of optical and fluidic elements on a single chip-based platform, is a rapidly developing field of study that is poised to take advantage of these unique fabrication abilities of FLP. Optofluidic devices are being explored for lab-on-a-chip and sensing applications by utilizing optical analysis techniques such as absorption or refractive index measurements on coupled fluidic channels and are an ideal means for making complex chemical measurements available outside the standard laboratory setting. In this work, the femtosecond laser photo-response of new Chalcogenide glasses is studied and the optimization of photo-induced modifications through laser processing conditions such as laser repetition rate and laser dose are discussed. In addition, FLP is used for the fabrication of optical and microfluidic elements towards the fabrication of integrated optofluidic sensors. Chalcogenide glasses with tailored chemical compositions are of particular interest as new substrate materials for FLP due to their structural flexibility, an ability to "tune" the glass properties through their chemical composition, and high IR transparency, which enables sensing biological and chemical analytes with spectral fingerprints in regions of the spectrum where many optical materials absorb.