Recently, the group of associate research fellow Li Guanhai and research fellows Chen Xiaoshuang, and Lu Wei from the Hangzhou Institute for Advanced Study (HIAS), UCAS, has worked with the group of Professor Andrey E. Miroshnichenko from the University of New South Wales, Australia. By leveraging the unique manipulation of the metasurface on the polarization, phase, and dispersion of medium-wave infrared photons, they proposed a high-efficiency multifunctional polarization-dispersion modulated ultrastructural photonic device (as shown in Fig. 1) for the integration of medium-wave infrared polarization detection. Their findings were published online inScience Advances underScience, with the title of "Mid-infrared Polarization-Controlled Broadband Achromatic Metadevice",doi.org/10.1126/sciadv.abc0711. HIAS is the second completion unit.
Fig. 1(A): Schematic Diagram of Polarization-Controlled Broadband Achromatic Aberration Focused Vortex Beam Generation on a Multifunctional Silicon-based Metasurface. Fig. 1(B): Curves of Lateral Displacement of Spot Center with Wavelength under Different Polarization States. Fig. 1(C): Polarization Extinction Ratio Measured at Different Wavelengths. Fig. 1(D): Full Width at Half Maximum and Theoretical Limit of Focused Spot at Different Wavelengths.
The lens is the simplest and most common optical component. Whether it is a camera phone, a digital camera for professional photography, or an astronomical telescope for observing the origin of the universe and the law of celestial movement, lenses are needed to achieve precise and complex functions. Traditional optical components are almost all mechanically ground and polished to achieve special curved surface configurations, which have problems such as large volume and weight, single photon regulation dimension and difficulty in integration, especially in fields more sensitive to volume and weight such as aerospace. Polarization detection is to suppress background noise by extracting specific polarization information on the basis of traditional intensity imaging, which has unique advantages for the detection and identification of camouflaged or false targets. Traditional polarization detection systems use discrete polarizers, prisms and lenses cascaded by amplitude division, time division or pixel division to obtain polarization information. Such optical systems are usually large in volume and weight, without achromatic aberration, which limits the wide-band polarization photoelectric integrated detection system. Therefore, it has become more and more urgent to develop miniaturized and integratable polarization-dispersion modulated optical devices for infrared broadband applications. Metasurface devices have a thinner and more compact planar spatial configuration, and more importantly, they can selectively manipulate photons in multiple dimensions at sub-wavelength scales, which provides us with opportunities in the atmospheric window-medium-wave infrared band with important application background.
In this research, a pair of "3D glasses" thinner than a piece of paper was made through exposure and etching processes compatible with silicon-based integrated circuits, which could focus, deflect and disperse light in different polarization states and different colors. Its performance was also comparable to that of traditional optical systems made of a series of cascade lenses, prisms, and polarizers. As shown in Fig. A, within a continuous design bandwidth, photons with different polarization states will carry different orbital angular momentum information after being modulated by a metasurface device and collected on a set focal plane. In addition, by introducing an off-axis phase factor into the modulated polarization-phase dispersion spectrum of the super-surface device, non-dispersion directional beam modulation was achieved for broadband beams. Due to the joint manipulation of polarization states, incident photons of different polarization states in a continuous bandwidth were also collected and converged to different design regions of the focal plane with high polarization isolation (Fig. 1B). The results show that the focused spot has a size close to the diffraction limit and a high polarization selective ratio (Fig. 1C, Fig. 1D). The research results are expected to be applied in fields such as broad-spectrum polarization imaging, free-space quantum communication, machine vision and information encryption. Associate research fellow Li Guanhai, research fellow Chen Xiaoshuang and Professor Andrey E. Miroshnichenko are the co-corresponding authors of the article, and doctoral candidates Ou Kai and Yu Feilong are the co-first authors of the article.
The research was supported by the Special Project on Quantum Regulation and Quantum Information of the Key R&D Program of the Ministry of Science and Technology, National Natural Science Foundation of China, Science and Technology Commission of Shanghai Municipality, Youth Innovation Promotion Association of Chinese Academy of Sciences, and the Innovation Program of the Shanghai Institute of Technical Physics.
Editor | Jiang Xuchen
