## 2 Special Issue Papers
They review the various approaches of producing dynamic holographic displays and show their particular proposal with a superior light efficiency and fault tolerance. Holographic displays favor small pixel devices, with LCoS devices as optimum candidates for these applications to become commercially feasible. [PERSON] et al. [13], in imaging applications, demonstrate a programmable zoom lens system where the magnification and sense of the image can be controlled without moving any parts. They use two programmable SLMs onto which they encode the required focal length lenses to achieve these results. They show both theoretical calculations and experimental results. The authors discuss the system's size limitations caused by the limited spatial resolution, and show how newer devices--LCoS with a very high resolution--would shrink the size of the system. SLMs are also used in holographic data storage systems (HDSS). The paper by [PERSON] et al. [14] presents a method to characterize a complete optical HDSS. In this study, the authors identify the elements that limit the capacity to register and restore the information introduced by means of a LCoS microdisplay as the data paper. They further test whether the anamorphic and frequency-dependent effect is relevant in the application to HDSS, where nonperiodic binary elements are applied. They consider anamorphic patterns with different resolutions addressed to the LCoS. They show both the precharacterization results when no recording material is in the HDSS and when introducing a photopolymer as the recording material. Another interesting application for LCoS devices is described by [PERSON] et al. [15]. Multimode fibers (MMF) are promising candidates for increasing the data rate while reducing the space required for optical fiber networks. The authors demonstrate a method for measuring the transmission matrix (TM) of a multimode fiber. It is based on mode-selective excitation of complex amplitudes performed with only one phase-only spatial light modulator. The light field propagating through the fiber is measured holographically and analyzed by a rapid decomposition method. The TM determines the amplitude and phase relationships of the modes, allowing us to understand the mode scrambling processes in the MMF, which can also be used for mode division multiplexing in telecommunications. In the review paper by [PERSON] et al. [16], the authors demonstrate an LCoS self-calibration technique, from which they perform a complete LCoS characterization. They determine its phase-voltage curve by using the interference pattern generated by a digital two-sectorial split-lens configuration. They also determine the LCoS surface profile by using a self-addressed dynamic microlens array pattern. Once the LCoS is calibrated, they show both the application to microparticle manipulation through light optical traps created by a LCoS display. They also show the ability of the LCoS display to implement a holographic imaging system with a double-sideband filter configuration, so as to obtain dynamic holographic imaging of microparticles. In the last paper of this collection, [PERSON] and [PERSON] [17] characterize a LCoS with a phase modulation much larger than 2\(\pi\) radians. Multiorder diffractive optical elements, displayed on the LCoS SLM with the appropriate phase modulation range, enable the design and experimental demonstration of an achromatic multiorder lens. They show that the residual chromatic aberration is reduced to one-third that of the chromatic aberration of a conventional first-order diffractive lens.