## 1 Introduction  
Since the first laser developments, Holographic Data Storage Systems (HDSS) have been a promising and appealing technology for true 3D storage of information and associative memory retrieval [1, 2]. There are some scientific and technological challenges to fulfill when a HDSS is developed [3, 4]. Our group evaluated the introduction of some novelties in the HDSS. One of these is the introduction of a parallel-aligned liquid crystal on silicon (PA-LCoS) microdisplay [5]. The PA-LCoS acts as data paper, and we designed some modulation schemes for it [6]. In this paper, we present a characterization method that allows us to evaluate the limitations introduced by different elements in our optical system. In previous works, we developed a characterization method for PA-LCoS, enabling to characterize the flicker effects produced because of the digital addressing technology, and also to characterize the retardance introduced [7]. In the literature, other degradation phenomena have also been detected and analyzed related not only with modern PA-LCoS microdisplays but also with previous liquid crystal displays (LCD). An important one is the anamorphic and frequency dependent effect [8; 9; 10; 11] that causes a reduction in the performance depending on the spatial frequency and on the orientation of the image displayed. In this sense, the anamorphic frequency dependent effect is exhibited by liquid crystal displays (LCDs) [8; 9; 11] and by modern LCoS devices, both digital [10] and analogically [11] driven. In LCDs, it was demonstrated [9] that the anamorphic phenomenon was directly related with the electronics driving the device. In general, the electrical signal corresponding to an image addressed to the display is produced by multiplexing the rows composing the image, where each row contains the voltage value to be applied to each of the pixels in the row. As a result, the horizontal (or pixel) frequency in the electrical signal is much larger than the vertical (or row) frequency. The limited bandwidth of the electronics driver will then produce a low-pass filtering for the horizontal frequency components in the image, especially if the image contains fast variations along the horizontal. This low-pass filtering of the electrical signal is then reflected on the reduction of the phase modulation range available when displaying phase-only diffractive optical elements [8]. The anamorphic and frequency dependent phenomenon has also been reported when using the LCD in the amplitude-only regime [3; 12; 13; 14; 15]. The authors were interested on the characterization of the modulation transfer function (MTF) of the LCD for its application in optical processing [12; 13; 14]. In [3] (p. 247) and [15], the LCD is applied in holographic data storage, which is also the focus of the present paper. Besides the effects produced by the limited electronics bandwidth already described, interpixel effects in the LC layer may also cause a reduction in the spatial frequency bandwidth. These interpixel effects are the fringing-field (i.e., appearance of tangential components in the applied electric field) and vicinity LC adherence effects that appear as a result of the competition between the tangential components of the applied field and the intermolecular forces within the liquid crystals (i.e., avoiding abrupt changes in the orientation) [16; 17; 18; 19; 20; 21; 22]. These interpixel effects are becoming more and more important in modern LCoS devices as the pixel size is becoming increasingly small, even smaller than 4 \(\upmu\)m [22], thus decreasing the ratio between the pixel size and the LC layer thickness (i.e., the cell gap). We also note that vicinity LC adherence effects exhibit an anamorphic behavior, as described in numerical simulations by [PERSON] et al. [18], depending on whether the applied electric voltage gradient is along the LC director at the alignment layers or perpendicular.