Abstract
We propose a method to generate two-dimensional phase-shift patterns (PSPs) in the optical far field using a holographic projection system (HPS), which can be used to fabricate non-periodic features. The field function of PSP is used as the target function to calculate the phase-only diffractive optical element by applying an optimization of modified iterative Fourier transform algorithm (IFTA). Using the phase-only diffractive optical element as the input to the spatial light modulator (SLM) of holographic projection system, an image resembling the PSP target is obtained in the projection plane. In contrast to the PSPs, which are the images of the input to the SLM, the PSPs of the proposed method are proportional to the squared modulus of the Fourier transform of the light field from the input SLM. The results of the proposed approach can lead to the development of a novel approach that combines the promising properties of the small critical dimension achieved by the phase-shift lithography (PSL) and the high velocity and low cost of the maskless lithography (ML).