Gradual transmittance controllable device via ion intercalation for spatial light modulators

To obtain realistic images, three-dimensional (3D) display technologies that have no spatial limitations are garnering attention. To implement the 3D display, stereoscopic and volumetric displays have been proposed. Among them, as one of the volumetric displays, a hologram is considered as an effective technology because it can generate the 3D display without causing additional virtual fatigue, such as eyestrain or nausea; moreover additional tools, such as glasses or screens are not required in this case [1]. The hologram can project 3D information of objects via interference and diffraction of light which are easily generated by spatial light modulators (SLMs). In addition, when diffraction angle of the SLM becomes larger, more detail 3D information of objects can be expressed. Thus, to enlarge the diffraction angle, the SLM requires smaller pixel size closed to visible light wavelength (VL-lambda: 380 similar to 780 nm) [2]. However, there exist a challenge when fabricating the VL-lambda sized SLM by typical fabrication technologies such as liquid crystal or micro-mirrors. It is because unit cell size of the liquid crystal and micro-mirrors requires more than few micrometers [3-7]. Therefore, we propose a novel approach that utilizes ion intercalation. When we consider the ion intercalation, the movement and intercalation of nano sized ion are the main operation mechanism. Based on this, the unit cell can be scaled down to nano scale. The size of unit cell limits only number of reacted ions. Thus, ratio of transmittance change could become smaller in To realize a hologram that is an effective method for implementing three-dimensional display, a novel spatial light modulator (SLM) that can generate the hologram by light interference and diffraction was developed based on transmittance changes. For a high-resolution hologram, pixel size of the SLM needs to be scaled down to visible light wavelength (380 similar to 780 nm). However, conventional liquid crystal or micro-mirror-based SLM has a limitation in scaling down; few micrometers sized unit parts are required based on its operation mechanism. Herein, an ion intercalation-based SLM utilizing nano-scale ions as the unit part was investigated. Consequently, basic operations of the SLM (light interference and diffraction) are achieved based on the gradual transmittance changes, which demonstrates the feasibility of ion intercalation-based SLM.

Automated summary

Hologram is considered as an effective technology for realistic 3D display without causing additional virtual fatigue, and does not require additional tools such as glasses or screens. Spatial light modulator is a key technology that can generate 3D information of objects via interference and diffraction of light.