Si metasurface half-wave plates demonstrated on a 12-inch CMOS platform

Abstract

Half-wave plate (HWP) is one of the key polarization controlling devices in optical systems. The conventional HWPs based on birefringent crystals are inherently bulky and difficult to be monolithically integrated with other optical components. In this work, metasurface-based HWPs with high compactness are demonstrated on a 12-inch silicon complementary metal-oxide-semiconductor platform. Three-dimensional finite difference time domain simulation is used to design the nanostructure and investigate the impact of fabrication process variation on the device performance. In addition, the cross- and co-polarization transmittance (Tcross and Tco) of the HWPs located at different wafer locations are characterized experimentally. The peak Tcross and valley Tco values of 0.69 ± 0.053 and 0.032 ± 0.005 are realized at the wavelength around 1.7 μm, respectively. This corresponds to a polarization conversion efficiency of 95.6% ± 0.8%.

Scalable and High-Throughput Top-Down Manufacturing of Optical Metasurfaces

“…Existing optical waveplates require a large volume to accumulate the required phase differences for various polarizations. A metasurface-based half-wave plate (HWP) was fabricated with a 12 inch feature size by DUV photolithography ( Figure 2 f) [ 71 ]. The polarization conversion efficiency, which indicates the primary figure of merit for a HWP, is defined as , where and are cross- and co-polarized transmittances, respectively.…”

“…(e) (i) Schematic of a reflective scanning microscopy using the metalens, (ii) the measured image of the United States Air Force resolution chart and (iii) a Siemens star using this reflective scanning microscopy. (f) (i) Photograph of a 12 in Si metasurface, (ii) schematic of a measurement system of Fourier-transform infrared (FT-IR) spectroscopy using the metasurface-based half-wave plate (HWP)[71]. (g) (i) Photograph of a centimeter-scale perfect absorber fabricated by photolithography, (ii) simulated and experimental spectra of the perfect absorber[74].…”

“…(g) (i) Photograph of a centimeter-scale perfect absorber fabricated by photolithography, (ii) simulated and experimental spectra of the perfect absorber[74]. Reproduced with permission from (a,b)[69]; ACS Publications, 2019, (c-e)[70]; Copyright 2019 American Chemical Society, (f)[71]; De Gruyter, 2012, and (g)[74]; Royal Society of Chemistry, 2015.…”

Spectral imaging and spectral LIDAR systems: moving toward compact nanophotonics-based sensing

“…In the near future, research and development efforts can be focused on the following three aspects, to facilitate the miniaturization of the multispectral/hyperspectral imaging and LIDAR systems. Firstly, with the demonstration of various metasurface-based functional devices, especially the spectral filters [169][170][171][172][173][174][175], it is expected to have more system-level integration of these devices (e.g., monolithic integration with CIS), to achieve compact spectral imaging systems. The monolithic fabrication process can be developed based on the mature CMOS fabrication technology.…”

Metasurfaces for biomedical applications: imaging and sensing from a nanophotonics perspective

“…Such metasurface-based flat devices represent a new class of optical components that are compact, flat, and lightweight. Numerous devices based on metasurfaces have been developed, including metasurface lenses (metalenses) [9][10][11][12][13][14][15][16][17][18][19], waveplates [20][21][22][23], polarimeters [24][25][26], and holograms [27][28][29]. For metalenses, in particular, numerical aperture (NA) as high as 0.97 was demonstrated [15].…”