Spin‐Decoupled Transflective Spatial Light Modulations Enabled by a Piecewise‐Twisted Anisotropic Monolayer

Abstract

Wavefront control lies at the heart of modern optics. Metasurfaces with specifically tailored resonators can encode different phases to two orthogonal polarization components, but suffer from wavelength‐dependent efficiency, sophisticated fabrication, and limited size. Liquid crystals, another excellent candidate for planar optics, are restricted to spin‐coupled conjugated phase modulations. Planar optics with spin‐decoupled functions is expected to release the multifunctionality of modern optics. Here, a spin‐decoupled transflective spatial light modulator is presented with a piecewise‐twisted anisotropic monolayer. The phases of reflected and transmitted light can be independently customized by preprogramming the initial orientations of the periodic helix and mirror‐symmetric dual‐twist configuration, respectively. A transflective orbital angular momentum encoder and decoder is demonstrated, which is simultaneously compatible with different multiplexing techniques. This work releases the multifunctionality of advanced planar optics and may upgrade existing devices in optical informatics.

Wavelength-adaptive optical angular momentum recognizer via programmable soft materials

“…Notably, beyond the proof-of-principle demonstration that highlights the recognition of a single CPOV mode, as well as the CVB or CVVB integrated by a pair of such modes, more complex beams superimposed by multiple independent CPOV modes can also be recognized from the corresponding diffraction orders with the partial Gaussian profile. 30 In addition, higher-order diffraction vortex arrays ( n x × n y ) can be acquired by upgrading the NLC microstructure with more delicate phase patterns, which is believed to substantially enhance the capability of angular momentum recognition with plenty of individual channels to detect the respective OAM states; on the other hand, for the optical matrix encoding, an enlarged scale of matrix can be established, thus leading the capacity of encoded information to be exponentially expanded in the form of 2^( n x × n y ). Furthermore, an alternative encoding method can be considered where the separated diffraction arrays are integrally regarded as one matrix.…”

“…26,27 A variety of geometric phase microstructures based on both nematic LCs (NLCs) or cholesteric LCs (CLCs) have been elaborately designed to not only efficiently create the CPOV beams, 28,29 but also measure various OAM states via detecting the optical field of featured diffraction arrays. 30 Nonetheless, the recognition of SAM is ambiguous since the diffraction behaviour of patterned NLCs is generally independent of SAMs, while CLCs can only respond to the certain SAM state that matches their helical handedness. In view of these circumstances, the accurate recognition of both SAM and OAM based on the LC device remains challenging.…”

Immersion‐Triggered Active Switch for Spin‐Decoupled Meta‐Optics Multi‐Display

“…Note that in our design, because the chosen unit cell is achiral, the geometric phases (ϕ PB = 2θ) should exhibit the same absolute values but with opposite signs (ϕ PB or -ϕ PB ), depending on the spin of incident polarizations (LCP or RCP, respectively). [49,50] In order to decouple the phase maps, we utilize the spin-independent propagation phases of the nanopillars (ϕ air and ϕ liq ), which relate to the nanopillar dimensions and surrounding states, as shown in Figure 2b. For The phase differences are designed to vary linearly from −3π/2 to 3π/2 with an interval of π/2 for the seven structures.…”

Reflective optical vortex generators with ultrabroadband self-phase compensation

“…Their maximum efficiencies always occur at the half-wave condition, and the efficiency drops significantly when the wavelength deviates. Helical structures are introduced to LC planar optics for broadband high-efficient phase modulation 14 , 15 . Mirror-symmetric multi-twist configurations endow transmissive LC planar optics with an ultrabroadband working frequency range 16 …”