An all-silicon design of a high-efficiency broadband transmissive terahertz polarization convertor

Abstract

Polarization, a fundamental behavior of electromagnetic waves, holds immense potential across diverse domains such as environmental monitoring, biomedicine, and ocean exploration. However, achieving efficient modulation of terahertz waves with wide operational bandwidth poses significant challenges. Here, we introduce an all-silicon polarization converter designed specifically to operate in the terahertz range of the electromagnetic spectrum. Simulation results demonstrate that the average conversion efficiency of cross-linear waves exceeds 80% across a wide frequency range spanning from 1.00 to 2.32 THz, with the highest conversion efficiency peaking at an impressive 99.97%. Additionally, our proposed structure facilitates linear-to-circular polarization conversion with an ellipticity of 1 at 0.85 THz. Furthermore, by rotating the cross-shaped microstructure, active control over arbitrary polarization states can be achieved. To summarize, the proposed structure offers remarkable flexibility and ease of integration, providing a reliable and practical solution for achieving broadband and efficient polarization conversion of terahertz waves.

Key words： Broadband; High efficiency; Polarization conversion; All-silicon

References

1 Nie, X.Y., Zhang, Y.L., Xiang, F.D., Lu, J.G., Huang, X., Wang, K.J., Liu, J.S., Yang, Z.G.: Cross section measurements of scale-model tactical targets by using 0.1 THz compact radar system. Chin. Opt. Lett. 15, 112201 (2017)

2 Xiao, Z.Y., Yang, Q.J., Huang, J.G., Huang, Z.M., Zhou, W., Gao, Y.Q., Shu, R., He, Z.P.: Terahertz communication windows and their point-to-point transmission verification. Appl. Opt. 57, 7673–7680 (2018)

3 Seeds, A.J., Shams, H., Fice, M.J., Renaud, C.C.: Terahertz photonics for wireless communications. J. Lightwave Technol. 33, 579–587 (2015)

4 Funaki, C., Toyouchi, T., Hoshina, H., Ozaki, Y., Sato, H.: Terahertz imaging of the distribution of crystallinity and crystalline orientation in a poly(ϵ-caprolactone) film. Appl. Spectrosc.Spectrosc. 71, 1537–1542 (2017)

5 Guerboukha, H., Nallappan, K., Skorobogatiy, M.: Toward real-time terahertz imaging. Adv. Opt. Photon. 10, 843–938 (2018)

6 Caucheteur, C., Guo, T., Albert, J.: Polarization-assisted fiber Bragg grating sensors: tutorial and review. J. Lightwave Technol. 35, 3311–3322 (2017)

7 Haigh, J.A., Kinebas, Y., Ramsay, A.J.: Inverse conoscopy: a method to measure polarization using patterns generated by a single birefringent crystal. Appl. Opt. 53, 184–188 (2014)

8 Przhiyalkovskiy, Y.V., Starostin, N.I., Morshnev, S.K., Sazonov, A.I.: Polarization dynamics of light propagating in bent spun bire-fringent fiber. J. Lightwave Technol. 38, 6879–6885 (2020)

9 Masson, J.B., Gallot, G.: Terahertz achromatic quarter-wave plate. Opt. Lett. 31, 265–267 (2006)

10 Kaveev, A.K., Kropotov, G.I., Tsygankova, E.V., Tzibizov, I.A., Ganichev, S.D., Danilov, S.N., Olbrich, P., Zoth, C., Kaveeva, E.G., Zhdanov, A.I., Ivanov, A.A., Deyanov, R.Z., Redlich, B.: Terahertz polarization conversion with quartz waveplate sets. Appl. Opt. 52, B60–B69 (2013)

11 Zhilin, A.A., Tagantsev, D.K., Alemaskin, M.Y., Shepilov, M.P., Zapalova, S.S., Sazonov, M.E.: Metamaterials with a network structure. J. Opt. Technol. 79, 241–245 (2012)

12 Wang, J., Wang, S., Singh, R.J., Zhang, W.L.: Metamaterial inspired terahertz devices: from ultra-sensitive sensing to near field manipulation. Chin. Opt. Lett. 11, 011602 (2013)

13 Cheng, Y.Z., Zhu, X.Z., Li, J., Chen, F., Luo, H., Wu, L.: Terahertz broadband tunable reflective cross-polarization convertor based on complementary cross-shaped graphene metasurface. Phys E Low Dimens. Syst. 134, 114993 (2021)

14 Zhu, X. Z., Cheng, Y. Z., Fan, J. P., Chen, F., Luo, H., Wu, L.: Switchable efficiency terahertz anomalous refraction and focusing based on graphene metasurface. Diamond Relat Mater. 121,108743 (2022)

15 Cheng, Y., Yu, J., Li, X.: Tri-band high-efficiency circular polarization convertor based on double-split-ring resonator structures. Appl. Phys. B 128, 1 (2022)

16 Zhao, J., Li, N., Cheng, Y.: All-dielectric InSb metasurface for broadband and high-efficient thermal tunable terahertz reflective linear-polarization conversion. Opt. Commun.Commun. 536, 129372 (2023)

17 Li, N., Zhao, J.C., Tang, P.Y., Cheng, Y.Z.: Design of all-metal 3D anisotropic metamaterial for ultrabroadband terahertz reflective linear polarization conversion. Phys Status Solidi B Basic Res. 260, 2300104 (2023)

18 Sun, H., Zhang, Y.X., Wang, K.L., Zhao, Y.C., Kou, W., Liang, S.X., Han, J.G., Yang, Z.Q.: Linear polarization conversion of transmitted terahertz wave with double-layer meta-grating surfaces. Chin. Opt. Lett. 16, 081601 (2018)

19 Cheng, Z.Z., Cheng, Y.Z.: A multi-functional polarization convertor based on chiral metamaterial for terahertz waves. Opt. Commun. Commun. 435, 178–182 (2019)

20 Zi, J.C., Ji, Y.F., Xi, F., Xu, Q., Liu, H.C., Zhang, X.X., Han, J.G., Zhang, W.L.: Dual-functional terahertz waveplate based on all-dielectric metamaterial. Phys. Rev. Appl. 13, 034042 (2020)

21 Kumar, A., Ghatak, A.: Polarization of light with applications in optical fibers. SPIE Press, Bellingham, WA, USA (2011)

22 Zi, J., Xu, Q., Wang, Q., Tian, C., Li, Y., Zhang, X., Han, J., Zhang, W.: Terahertz polarization converter based on all-dielectric high birefringence metamaterial with elliptical air holes. Opt. Commun.Commun. 416, 130–136 (2018)

23 Maxwell, J.C.: A treatise on electricity and magnetism. Clarendon Press, UK (1873)

24 Born, M., Wolf, E.: Principles of optics. Cambridge University Press, London (1999)

25 Veselago, V.G.: The electrodynamics of substances with simultaneously negative values of ϵ and μ. Soviet Physics Uspekhi 10, 509 (1968)

26 Fu, X., Cui, T.J.: Recent progress on metamaterials: from effective medium model to real-time information processing system. Prog. Quantum Electron. 67, 100223 (2019)

27 Li, J., Zheng, C.L., Li, J.T., Wang, G.C., Liu, J.Y., Yue, Z., Hao, X.R., Yang, Y., Li, F.Y., Tang, T.T., Zhang, Y.T., Zhang, Y., Yao, J.Q.: Terahertz wavefront shaping with multi-channel polarization conversion based on all-dielectric metasurface. Photonics Res. 9, 1939–1947 (2021)

28 Yan, W., Li, S., Hui, W., Feng, L., Tan, B., Tan, Y., Su, R., Wu, J., Zhang, C., Jin, B., Chen, J., Wu, P.: Broadband and efficient asymmetric wavefront manipulation via terahertz polarization-selective metasurface. Appl. Phys. Lett. 121, 151701 (2022)

29 Lian, M., Ying, S., Liu, K., Zhang, S., Chen, X., Ren, H., Xu, Y., Chen, J., Tian, Z., Cao, T.: Nonvolatile switchable broadband polarization conversion with wearable terahertz chalcogenide metamaterials. Adv. Opt. Mater. 11, 2202439 (2023)

30 Peng, Z., Zheng, Z., Yu, Z., Lan, H., Zhang, M., Wang, S., Li, L., Liang, H., Su, H.: Broadband absorption and polarization conversion switchable terahertz metamaterial device based on vanadium dioxide. Opt. Laser Technol. 157, 108723 (2023)

31 Tao, X., Qi, L., Yang, J., Uqaili, J., Lan, F., Yang, Z.: Bifunctional terahertz metasurface for transmissive broadband linear-to-circular and linear polarization conversion. IEEE T THz Sci. Techn. 13, 254–261 (2023)

32 Gutiérrez-Vega, J.C.: Pancharatnam-Berry phase of optical systems. Opt. Lett. 36, 1143–1145 (2011)

33 Tian, Y., Jing, X.F., Yu, H., Gan, H.Y., Li, C.X., Hong, Z.: Manipulation of the arbitrary scattering angle based on all-dielectric transmissive Pancharatnam Berry phase coding metasurfaces in the visible range. Opt. Express 28, 32107–32123 (2020)

34 Zi, J., Xu, Q., Wang, Q., Tian, C., Li, Y., Zhang, X., Han, J., Zhang, W.: Antireflection-assisted all-dielectric terahertz meta-material polarization converter. Appl. Phys. Lett. 113, 101104 (2018)

35 Sakurai, H., Nemoto, N., Konishi, K., Takaku, R., Sakurai, Y., Katayama, N., Matsumura, T., Yumoto, J., Kuwata-Gonokami, M.: Terahertz broadband anti-reflection moth-eye structures fabricated by femtosecond laser processing. OSA Continuum. 2, 2764–2772 (2019)

36 Tan, G.J., Lee, J., Lan, Y.H., Wei, M.K., Peng, L.H., Cheng, I.C., Wu, S.T.: Broadband antireflection film with moth-eye-like structure for flexible display applications. Optica 4, 678–683 (2017)