Nanostructuring in submicron-level waveguides with femtosecond laser pulses

Summary form only given. In early 2000, we demonstrated the capability of a femtosecond laser with a UV wavelength of 387 nm to drill 200-250 nm holes in Si-on-SiO/sub 2/ substrate. It met the spacing requirement for 1D waveguide photonic crystal. We then took the next step to study drilling small holes on actual waveguides Promising drilling results on waveguides were achieved, and a forbidden transmission zone or photonic band gap was discovered from the laser-machined waveguides during our preliminary measurement. Our best drilling results were obtained recently. On 600 nm wide waveguides, we drilled 8 holes (diameter /spl sim/ 200 nm) with pitch size of 400 nm. Reasonable uniformity in hole-size and hole-shape was obtained, and holes were pretty well positioned.