Phase calibration of spatial light modulators by means of Fresnel images

Abstract

Reliable application of spatial light modulators (SLMs) as programmable diffractive optical elements requires a thorough calibration. In this paper, we propose a method for calibrating SLMs based on the evaluation of Fresnel images. Fresnel images generated by a binary phase diffraction grating consist of binary irradiance distributions whose visibility depends on the phase modulation. By displaying on our device a diffraction grating with a binary phase step along one direction and a linearly increasing phase along the orthogonal direction, we perform a complete phase calibration. In this way, the phase modulation for every pixel and for every value of the entrance signal can be determined experimentally.Additionally, data acquisition can be significantly simplified with this scheme.

Diffractive gratings with varying period’s shape

“…φmax is the maximum phase change obtainable with the SLM device and Dy is the periods length, makes it possible to observe the resulting distribution of the visibility function in the corresponding Fresnel image in a manner similar to the interference fringe pattern with a carrier frequency, and not in a uniform field, as was the case in some of the previous approaches [33]. The visibility function of the Fresnel images in the case of perfect SLM takes then the following form of equidistant fringes:…”

High-Precision Calibration of Phase-Only Spatial Light Modulators

“…The former leads to dynamic phase response errors, while the latter results in static wavefront aberrations. To meet the requirement of high-precision wavefront controlling in practical applications, a variety of calibration schemes for compensating the phase distortion have been developed, which are mainly based on three types of measuring principles: interferometry [11]- [14], diffraction technique [15]- [18] and polarimetry [19]- [21]. The three schemes have their pros and cons: interferometric methods are appreciated as the high-precision measurement but are susceptible to environmental vibration; diffraction methods are robust against environmental disturbance but cannot afford spatially varying phase modulation measurement, thereby lacking the ability of pixel-wise calibration; polarization measurement can characterize electro-optic birefringence property of the LC, but the phase estimation operation via birefringence-based optical modeling is a rather complicated process and is usually challenging to achieve pixel-wise phase measurement.…”

Pixel-addressable phase calibration of spatial light modulators: a common-path phase-shifting interferometric microscopy approach

“…For this purpose, the high precision phase calibration of SLM is required because normally a commercial SLM has a nonlinear and spatially varying phase response. Many measurement and calibration procedures have been developed in the literature, including two-beam interference techniques, such as doubleslit interference recommended by manufacturers [5,6] or widely used two-arm interference [7][8][9][10], the shearing interferometric method [11], diffractive grating method [12][13][14], diffraction-based phase retrieval [15][16][17], polarimetric measurement [18][19][20][21] and so on. In the two-beam interference technique, the beams reflected off two different areas (e.g.…”