Supporting information. Versatile Polarization Generation with an Aluminum Plasmonic Metasurface

Transcription

1 Supporting information Veratile Polarization Generation with an Aluminum Plamonic Metaurface Pin Chieh Wu,, Wei-Yi Tai, Wei Ting Chen, Yao-Wei Huang, Ting-Yu Chen, Jia-Wern Chen, Chun Yen Liao, Cheng Hung Chu, Greg Sun, 3 and Din Ping Tai,,,4,* Reearch Center for Applied Science, Academia Sinica, Taipei 59, Taiwan Department of Phyic, National Taiwan Univerity, Taipei 067, Taiwan 3 Department of Engineering, Univerity of Maachuett Boton, Boton, Maachuett 05, United State 4 College of Engineering, Chang Gung Univerity, Taoyuan 3330, Taiwan *dptai@phy.ntu.edu.tw. Optimization of SiO layer thickne for the metaurface polarization generator The dielectric pacer SiO play a key role in optimizing the polarization converion. It thickne eparating the Al nanoantenna and underlying Al mirror affect their coupling trength which in turn determine the converion efficiency, co-polarization reflectance, and aborption that are plotted in Fig. S. It i can be een that when the SiO thickne i around 50 nm, the Al-nanoantenna/SiO /Al-mirror tructure yield the highet polarization converion efficiency over the viible range while uppreing copolarization reflectance and aborption over the viible range ( nm).

2 Figure S. Simulated (Left) polarization converion (cro-polarization) efficiency R cro for circularly polarized light, (Middle) co-polarization reflectance R co and (Right) aborption A = R cro R co a a function of SiO layer thickne and incident wavelength.. Fundamental reonance and half-wave plate behavior of Al nanoantenna Here we illutrate in the top panel of Fig. S(b) the fundamental reonance of Al nanoantenna in Fig. S(a) under a normal illumination with linearly polarized light. For x-polarized light, a reflectance dip around 350 nm reveal it plamon reonance along the hort-axi of Al nanoantenna, while for y-polarized light, the firt fundamental reonance along it long-axi appear around 850 nm. Between thee reonance, an abrupt phae hift i induced a light cattering off from the metaurface coniting of Al nanoantenna. It can be een from the bottom panel in Fig. S(b) that the phae difference of 80 between the x- and y-polarized light panning from around 400 to 770 nm i

3 obtained, indicating that the Al nanoantenna behave a a half-wave plate over the viible range which i needed for the broadband circular polarization converion. Figure S. (a) Schematic for Al plamonic nanoantenna. (b) Simulated (top) reflectance pectra for Al nanoantenna for x- and y-polarized normal illumination. Inet: x- and y-polarization relative to Al nanoantenna orientation. (Bottom) Phae difference for the x- and y-polarized cattered light. 3

4 3. COMS camera image Figure S3. Camera image of ix generated polarizing tate. Generation of ix polarization from an incident LP-H wave at variou incident wavelength when the polarizer (P) and quarter-wave plate are abent. Thee image are captured when ix metaurface area on a ingle chip are irradiated by a ingle incident beam. 4. Stoke parameter decription via Mueller matrix The Mueller matric M, which i a four-by-four matrix with real valued element, can be ued to decribe the tranformation of Stoke parameter of incident light into the cattered one when an incident light pae through a polarization altering component: S m m m m S m m m33 m 4 S S i S MS (S) S m 3 m m33 m 34 S S m 3 4 m m33 m44 S3 4

5 where S i and S repreent the Stoke vector of incident and cattered light, repectively. The Mueller matric M baically ha different formalim for different kind of polarization altering component uch a waveplate and polarizer etc. When a light beam pae through a equence of polarization altering component, the reulting Mueller matrix M can be directly obtained from the product of each individual matrix M t M M M M M M (S) T T t Baed on the optical etup hown in Fig. 4c, the cattered light from MPG will pa through a quarter-wave plate then a linear polarizer. According to eq. S, the final Stoke vector can be obtained by: S co in co in S in co in co S in co 0 S 3 (S3) where φ i the angle of fat axi of quarter-wave plate. The intenity variation of cattered light from MPG can be ubequently obtained: I( ) S0 S S3 in S co S in (S4) Compriing eq. (S4) with eq. (4) in the main text, all Stoke parameter of cattered light from deigned MPG can be ubequently obtained a S 0 = A C, S = C, S = D, S 3 = B. 5

6 5. Experimental verification of generated polarizing tate cro the viible pectrum range Figure S4. Experimental verification of generated polarizing tate at different incident wavelength. Experimental diagram of ignal intenity a a function of rotating angle of the quarter-wave plate for different incident wavelength. Figure S5. Poincaré phere experimental reult (color dot) compared with theoretical prediction (black dot) for incident wavelength λ = 500, 600 and 690 nm. 6