Contrast Analysis of Polarization in Three-Beam Interference Lithography

Abstract

This paper analyzes the effect of polarization and the incident angle on the contrasts of interference patterns in three-beam interference lithography. A non-coplanar laser interference system was set up to simulate the relationship between contrast, beam polarization, and the incident angle. Different pattern periods require different incident angles, which means different contrast losses in interference lithography. Two different polarization modes were presented to study the effects of polarization with different incident angles based on theoretical analysis simulations. In the case of the co-directional component TE polarization mode, it was demonstrated that the pattern contrast decreases with the increase in the incident angle and the contrast loss caused by the polarization angle error also grew rapidly. By changing the mode to azimuthal (TE-TE-TE) polarization, the contrast of the interference pattern can be ensured to remain above 0.97 even though the incident angle is large. In addition, TE-TE-TE mode can accept larger polarization angle errors. This conclusion provides a theoretical basis for the generation of high-contrast light fields at different incident angles, and the conclusion is also applicable to multi-beam interference lithography.

Analysis of the Polarization Distribution and Spin Angular Momentum of the Interference Field Obtained by Co-Planar Beams with Linear and Circular Polarization

“…It is known that when propagating in the far zone, radiation from a set of point sources corresponds to a superposition of plane waves [33]. Therefore, as a rule, the interference of plane waves created by a set of point sources (or small holes) is considered [27][28][29][30][33][34][35][36][37][38]. However, field 1 can also be focused using both conventional lenses and objective lenses.…”

“…Most works analyze the influence of the geometric arrangement of interfering beams and their polarization state on the contrast of the formed relief [27][28][29][30]. In this case, the TEor TM-polarization of beams is often considered with respect to the radius vector connecting the origin of the input plane and the center of the position of the corresponding beam.…”

“…Thus, with multi-beam interference, the influence of linear polarization with a certain configuration is studied. Note that the best contrast in lithography was predicted for structures formed by coplanar (diametrically spaced relative to the origin) pairs of beams [24,29,30] with TE polarization corresponding to the azimuthal configuration. When structuring polarization-sensitive materials, better contrast is achieved due to the interference of beams with orthogonal circular or diagonal polarizations, depending on the polymer type [23][24][25][26].…”

Optofluidic Micromachined Platform for Refractive Index Measurement

“…In-line fiber-optic RI sensors, including Fabry-Perot (FP) [14,15], Michelson [16,17], and Mach-Zehnder interferometers (MZI) [18][19][20][21][22][23], provide a relatively simple construction, which includes the splicing of two or more parts of optical fibers. Rao et al [14] presents a fiber-optic RI sensor which is based on an intrinsic Fabry-Perot interferometer (IFPI) made of a piece of endlessly single-mode photonic crystal fiber (EPCF) and a common single-mode fiber.…”

“…Eventually, the micromachined optofluidic platform may be easily manufactured as a Lab-on-the-Chip by 3D printing, polymer injection molding, and hot embossing for the sake of cost-effective mass production, e.g., for the single-use purpose in biomedicine and clinical diagnosis [22]. The light intensity at the output is described by the classical relation [23]:…”