Fabrication of Multiple Slanted Microstructures on Silica Glass by Laser-Induced Backside Wet Etching

Slanted microstructures were fabricated on silica glass by laser-induced backside wet etching (LIBWE) with gradual shift of the area irradiated by normal incidence. Slanted microtrenches with tilting angles up to about 30 degrees could be fabricated by lateral shift of the irradiated area with the speed of ~5.0 nm·pulse under the conditions showing the vertical etching with rate of 7.0 11 nm·pulse. Tilting angle could be controlled by the speed of lateral shift the irradiated area during the etching. Such structures were formed as a result of both lateral and vertical etching at the etch front. The trench structure fabricated by drastic shift of the irradiated area indicated that the etching of the sidewalls occurred at the area with height of around 400 nm.