Fig. 1. Conceptual illustration of the TRIM and its function demonstrations under x-LP normal illumination including beam splitting, vortex beams, and multifoci. The built-in zoom-in-view inset illustrates the detailed structure of the tetrameric meta-molecule consisting of two pairs of chiral meta-atoms. Red chiral meta-atoms are labeled as meta-atom A, and yellow chiral meta-atoms are labeled as meta-atom B. The meta-atom B can be viewed as a 180° mirror operation of the meta-atom A with respect to x-axis.

Fig. 2. Schematic diagram of the meta-atom A and its EM characteristics. (a) Perspective view of the meta-atom A. (b) Sectional view of the meta-atom A with geometric parameters. (c) Side view of the electric-field distributions for the meta-atom A under RCP (left two panels) and LCP (right two panels) normal incidence. (d), (e) Surface electric current distributions of the top (top panel) and bottom (lower panel) metallic copper layers under RCP and LCP normal incidence, respectively. (f) Simulated co-polarized and cross-polarized transmission amplitudes of the meta-atom A under orthogonal CP normal incidence. (g), (h) Simulated cross-polarized transmission phase delay φtLR versus rotation angles αA and βA of the meta-atom A under RCP normal incidence. (i) Simulated co-polarized and cross-polarized reflection amplitudes of the meta-atom A under CP normal incidence. (j), (k) Simulated co-polarized reflection phase delay φrLL versus rotation angles αA and βA of the meta-atom A under LCP normal incidence.

Fig. 3. Elaborate flow chart of the proposed TRIM design. The construction of the TRIM comprises three processes: phase decomposition, rotation angle mapping, and hybrid arrangement.

Fig. 4. Independent control of CP beam splitting enabled by the proposed TRIM1. (a), (b) The calculated spatial phase distributions in Lr-Li channel and Rr-Ri channel, respectively. (c), (d) The emerging spatial phase and corresponding rotation angle distributions of the meta-molecules on the top layer of the TRIM1, respectively. (e), (f) The calculated spatial phase distributions in Lt-Ri channel and Rt-Li channel, respectively. (g), (h) The emerging spatial phase and corresponding rotation angle distributions of the meta-molecules on the bottom layer of the TRIM1, respectively. (i), (j) The simulated 3D normalized far-field scattering patterns of combined different polarized components under x-LP normal incidence in the reflection and transmission space at 11 GHz, respectively. (k), (l) Photographs of the top and bottom layers of the fabricated TRIM1, respectively. Inset shows the enlarged view. The simulated and measured 2D normalized far-field scattering patterns at 11 GHz under x-LP normal incidence in the (m) ϕ=0° and (n) ϕ=90° planes in the reflection space and (o) ϕ=0° and (p) ϕ=90° planes in the transmission space.

Fig. 5. Generation of LP versatile vortex beams enabled by the proposed TRIM2. (a), (b) The calculated spatial phase distributions in Lr-Li channel and Rr-Ri channel, respectively. (c), (d) The emerging spatial phase and corresponding rotation angle distributions of the meta-molecules on the top layer of the TRIM2, respectively. (e), (f) The calculated spatial phase distributions in Lt-Ri channel and Rt-Li channel, respectively. (g), (h) The emerging spatial phase and corresponding rotation angle distributions of the meta-molecules on the bottom layer of the TRIM2, respectively. (i), (j) The simulated 3D normalized far-field scattering patterns of combined different polarized components under x-LP normal incidence in the reflection and transmission space at 11 GHz, respectively. (k), (l) Photographs of the top and bottom layers of the fabricated TRIM2, respectively. Inset shows the enlarged view. The simulated and measured 2D normalized far-field scattering patterns at 11 GHz under x-LP normal incidence in the (m) ϕ=0° and (n) ϕ=90° planes in the reflection space and (o) ϕ=0° and (p) ϕ=90° planes in the transmission space.

Fig. 6. Generation of CP and LP multifoci enabled by the proposed TRIM3. (a), (b) The calculated spatial phase distributions in Lr-Li channel and Rr-Ri channel, respectively. (c), (d) The emerging spatial phase and corresponding rotation angle distributions of the meta-molecules on the top layer of the TRIM3, respectively. (e), (f) The calculated spatial phase distributions in Lt-Ri channel and Rt-Li channel, respectively. (g), (h) The emerging spatial phase and corresponding rotation angle distributions of the meta-molecules on the bottom layer of the TRIM3, respectively. (i), (j) The simulated normalized electric-field intensity distributions of combined different polarized components on the xy plane cutting at z=+180  mm and z=−180  mm under x-LP normal incidence at 11 GHz, respectively. (k), (l) Photographs of the top and bottom layers of the fabricated TRIM3, respectively. Inset shows the enlarged view. The simulated and measured electric-field intensities scanned along (m) the x-direction at y=0  mm, (n) the y-direction at x=0  mm in the reflection plane (z0=+180  mm), (o) the x-direction at y=0  mm, and (p) the y-direction at x=0  mm in the transmission plane (z0=−180  mm) under x-LP normal incidence at 11 GHz.

Fig. 7. Broadband performance characterization of independent CP beam splitting enabled by TRIM1. The simulated 2D normalized far-field scattering patterns within 8–16 GHz under x-LP normal incidence in the (a) ϕ=0° and (b) ϕ=90° planes in the reflection space and (c) ϕ=0° and (d) ϕ=90° planes in the transmission space. The theoretical and measured results are represented by red lines and blue brilliant circles, respectively.

Fig. 8. Independent control of EP beam splitting enabled by the proposed TRIM4. (a), (b) The calculated spatial phase distributions in Lr-Li channel and Rr-Ri channel, respectively. (c), (d) The emerging spatial distributions and corresponding rotation angle distributions of the meta-molecules on the top layer of the TRIM4, respectively. (e), (f) The calculated spatial phase distributions in Lt-Ri channel and Rt-Li channel, respectively. (g), (h) The emerging spatial distributions and corresponding rotation angle distributions of the meta-molecules on the bottom layer of the TRIM4, respectively. (i), (j) The simulated 3D normalized far-field scattering patterns of elliptical left-handed circularly polarized (ELCP) component in the reflection space and elliptical right-handed circularly polarized (ERCP) component in the transmission space under ELCP normal incidence at 11 GHz, respectively. (k), (l) The simulated 3D normalized far-field scattering patterns of ERCP component in the reflection space and ELCP component in the transmission space under ERCP normal incidence at 11 GHz, respectively. The simulated 2D normalized far-field scattering patterns in the ϕ=0° plane within 8–16 GHz in the (m) reflection and (n) transmission spaces under ELCP normal incidence and in the (o) reflection and (p) transmission spaces under ERCP normal incidence.

Fig. 9. Performance characterization of near-field electric field for the generated LP versatile vortex beams enabled by TRIM2. The simulated 2D normalized (a)–(d) amplitude and (e)–(h) phase distributions for vortex beams with x-LP, u-LP, y-LP, and v-LP states in the reflection space, respectively. The simulated 2D normalized (i)–(l) amplitude and (m)–(p) phase distributions for vortex beams with x-LP, u-LP, y-LP, and v-LP states in the transmission space, respectively.

Fig. 10. Broadband performance characterization of LP versatile vortex beams generation enabled by TRIM2. The simulated 2D normalized far-field scattering patterns within 8–16 GHz under x-LP normal incidence in the (a) ϕ=0° and (b) ϕ=90° planes in the reflection space and (c) ϕ=0° and (d) ϕ=90° planes in the transmission space. The measured results are represented by blue brilliant circles.

Fig. 11. Measured results of the generated CP and LP multifoci enabled by TRIM3. (a), (b) The measured normalized electric-field intensity distributions of combined different polarized components on the xy plane cutting at z0=180  mm and z0=−180  mm under x-LP normal incidence at 11 GHz, respectively.

Fig. 12. Broadband performance characterization of CP and LP multifoci metalens in the reflection space enabled by TRIM3. The (a)–(d) simulated and (e)–(h) measured normalized electric-field intensity distributions on the xoz plane under x-LP normal incidence at 8 GHz, 11 GHz, 14 GHz, and 16 GHz, respectively. The (i)–(l) simulated and (m)–(p) measured normalized electric-field intensity distributions on the yoz plane under x-LP normal incidence at 8 GHz, 11 GHz, 14 GHz, and 16 GHz, respectively.

Fig. 13. Broadband performance characterization of CP and LP multifoci metalens in the transmission space enabled by TRIM3. The (a)–(d) simulated and (e)–(h) measured normalized electric-field intensity distributions on the xoz plane under x-LP normal incidence at 8 GHz, 11 GHz, 14 GHz, and 16 GHz, respectively. The (i)–(l) simulated and (m)–(p) measured normalized electric-field intensity distributions on the yoz plane under x-LP normal incidence at 8 GHz, 11 GHz, 14 GHz, and 16 GHz, respectively.

Fig. 14. Schematic illustration of the measurement setup. (a) The experimental setup for measurement of far-field pattern. (b), (c) The experimental setups for Ex and Ey components measurement of near-field pattern. (d) The photograph of the fabricated coaxial probe.