Project Title: 3D structure writing with laser
Project Leader: Zahidur R Chowdhury
Supervisor: Prof. Robert Fedosejevs
My role: Design of experiment, Optical system design, laser writing automation, trouble-shooting, and report writing.
Tools used: Spectra physics Ti-Sapphire Femto-second laser system / National Instrument's LabView / MATLAB / LATEX / Microsoft Office / Origin
Summary
- Three-dimensional (3D) microstructure writing using the two photon absorption (TPA) process has potential applications in the fabrication of photonic crystals and micromechanical devices. Ormocore and SU-8, two commercially available photoresists, were used to produce 3D structures and compare their writing performances. A 40X objective (NA 0.65) was used to produce high aspect ratio structures with high resolution. The resultant widths and heights of the lines written in the resists were measured for various exposure conditions. Walls with ~320 nm width and aspect ratios of 40 were produced in Ormocore. Other standing 3D structures were also written to demonstrate the capability of the resists.
- Figure: 3D structures fabricated with direct femto-second laser writing using two-photon absorption process.
Publication(s)
Zahidur R. Chowdhury and Robert Fedosejevs, “Two photon absorption coefficients and processing parameters for suitable photoresists”, J. of Microsystem and Microtechnolgy, vol. 14(1), pp. 59-67, 2008. view / link
Zahidur R. Chowdhury and Robert Fedosejevs, “Sub-micron resolution three dimensional structure writing using two photon absorption process”, presented in Photonics North, published in the Proceedings of SPIE, vol. 6343, article no. 634326, Quebec City, Canada 2006. view / link