Optical vortex beam direct-writing photolithography

By using a focused unit-order vortex beam generated by a spiral phase plate, it is possible to acquire similar to 100 nm structures in direct-writing photolithography. This novel method is simple and inexpensive and can quickly fabricate nanometer-size dams or trenches that may have applications in nanoscale waveguides or micro-and nanofluidics. To overcome the defect of a small exposure dose tolerance in this method, which may lead to poor quality of the direct-writing lines, an alternative solution using a fractional-order vortex beam is proposed. (C) 2018 The Japan Society of Applied Physics