Yu, XiaomingBian, QiumeiZhao, B.Chang, ZenghuCorkum, P. B.Lei, Shuting2013-05-062013-05-062013-02-01http://hdl.handle.net/2097/15747We report on the experimental study of microstructures fabricated on the surface of fused silica by two femtosecond laser pulses, a tightly focused 266 nm beam followed by a loosely focused 800 nm beam. By setting the fluence of each pulse below the damage threshold, visible microstructures are fabricated using the combined beams. Our results suggest that the ultraviolet pulse generates seed electrons through multiphoton absorption, and the near-infrared pulse utilizes these electrons to cause damage by avalanche ionization.en-USThis Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).MicrostructuresUltraviolet multiphoton ionizationText