Single pulse nm-size grating formation in polymers using laser ablation with an irradiation wavelength of 355 nm

Laser ablation at 355 nm of a specially designed polymer was used as a true single step dry-etching process to create a two-beam interference grating. Gratings with groove spacings of 180 and 1090 nm were created with single laser pulses. Moreover, by varying the laser fluence and/or the angle between the two beams, variable modulation frequencies (depth/spacing) could be obtained. Additional pulses deteriorated the grating quality, demonstrating the importance of the single pulse approach. (C) 1999 American Institute of Physics. [S0003-6951(99)00333-2].