Calibration of phase liquid crystal spatial light modulators using high-order Taiji radial-shearing interferometry

Abstract

The modulation characteristics of liquid crystal spatial light modulators (LC-SLMs) are related to the incident wavelength. In order to load the grayscale image correctly, LC-SLMs must be calibrated before using. We propose high-order Chinese Taiji radial-shearing interferometry to calibrate the phase modulation curve of an LC-SLM, which is different from the conventional calibration method. The new method is proposed to establish the mapping relationship between LC-SLM grayscale and phase modulation by rotating multiple Airy spots, which are derived from radial-shearing interference through a high-order Chinese Taiji lens. Compared with the traditional interference fringes, one of the greatest advantages is that the function between the grayscale and rotation angle of the two Airy spots is established more easily. Moreover, it eliminates the complex data processing steps and has a high enough signal-to-noise ratio. The experimental results show that high-order Chinese Taiji radialshearing interferometry is a very effective calibration method for LC-SLM.

High Precision Optical Wavefront Generation Using Liquid Crystal Spatial Light Modulator (LC-SLM)

“…Recently, a radial shear interferometry was proposed by sending a Chinese highorder Taiji lens onto SLM [25]. The optical setup is shown in Figure 6.…”

“…In addition, the gray level of the upper part gradually increases from 0 to 255 in 8 steps, which is called the test part. After the reflection of LC-SLM, the first-order Optical setup of the radial shear interferometry [25]. HWP-half waveplate, MO1-micro-objective, L1, L2 -lens, P-polarizer, A-analyzer.…”

“…Figure 6.Optical setup of the radial shear interferometry[25]. HWP-half waveplate, MO1-micro-objective, L1, L2…”

High-precision Shack-Hartmann wavefront sensing with a multi-focal diffraction Taiji-lenslet array

“…Because the optical path length between the even and odd zone plates is an integral number of half wavelengths, the two partitions with completely opposite phase values will produce two separate focal spots at each focal plane. Based on the standard Taiji-lens, we established a multifocal Taiji-lens to produce multiple focal spots in the far field [23]. If each Yin or Yang part is further divided into Yin and Yang sections, we can obtain a fourth-order Taijilens.…”