Metasurface-enabled polarization-independent LCoS spatial light modulator for 4K resolution and beyond

Abstract

With the distinct advantages of high resolution, small pixel size, and multi-level pure phase modulation, liquid crystal on silicon (LCoS) devices afford precise and reconfigurable spatial light modulation that enables versatile applications ranging from micro-displays to optical communications. However, LCoS devices suffer from a long-standing problem of polarization-dependent response in that they only perform phase modulation on one linear polarization of light, and polarization-independent phase modulation—essential for most applications—have had to use complicated polarization-diversity optics. We propose and demonstrate, for the first time, an LCoS device that directly achieves high-performance polarization-independent phase modulation at telecommunication wavelengths with 4K resolution and beyond by embedding a polarization-rotating metasurface between the LCoS backplane and the liquid crystal phase-modulating layer. We verify the device with a number of typical polarization-independent application functions including beam steering, holographical display, and in a key optical switching element - wavelength selective switch (WSS), demonstrating the significant benefits in terms of both configuration simplification and performance improvement.

Liquid crystal-integrated metasurfaces for an active photonic platform

“…In other research, improving the quality and functionality of SLMs are actively studied, which can contribute to wide range of applications such as displays, LiDAR, and optical communications. For example, a multispectral SLM has been proposed using LC-tunable FP nanocavities which enables high reflectance and 2π phase modulations at multiple wavelengths, a crucial feature for display applications 167 . The system comprises an LC layer sandwiched between two distributed Bragg reflector layers, with the thickness of each layer is carefully optimized to achieve high reflectance and large phase shifts at multiple wavelengths.…”

Generating Multi‐Depth 3D Holograms Using a Fully Convolutional Neural Network

“…CGHs can be discretized and printed on an optically sensitive medium, [ 20 , 21 ] encoded by a meta surface material, [ 22 , 23 ] or loaded onto the core component called the “spatial light modulator (SLM),” or even other novel optical modulator such as anisotropic leaky‐mode modulator, [ 24 ] to achieve a refreshable and dynamic 3D display. [ 25 , 26 , 27 ] The reconstructed 3D scene can be observed by the researchers at a designed location along the optical path. In addition to the 3D display, CGHs are also used in other fields such as interferometry, [ 28 , 29 ] beam shaping, [ 30 , 31 ] optoelectronic computing, [ 32 , 33 ] optical encryption, [ 34 , 35 ] and angular momentum holography.…”

DataSheet1.docx

“…SLMs manipulate the diffraction pattern of the output beam by introducing pixel-by-pixel variations in the amplitude, phase, or both of the incident light beams, relying on a sophisticated control system to modulate each pixel individually. In the present day, compact and high-speed spatial light modulator (SLM) devices predominantly rely on liquid crystal on silicon (LCoS) technology [23,24]. These devices utilize the nonlinear behavior of liquid crystals (LCs) to drive phase and amplitude shifters on a silicon chip.…”

“…Remarkably, this metasurface allows for mode switching among single-angular-mode (SAM), dual-angular-mode (DAM), and four-angular-mode (FAM), while consistently maintaining a sidelobe suppression ratio (SSR) below −9 dB. Compared with the LCoS SLMs [23,24] and OPA-based [20][21][22] beam generation and steering technologies, the DBSM exhibits remarkably versatile functionalities, all while being controlled by a system with only two degrees of freedom. Therefore, our proposed translation-controlled cascaded metasurface offers a concise pathway to realize dynamic multiple-beam generation and steering across various applications, including FSO communication, LiDAR, optical MIMO, and optical switching.…”