Photon sorting in the near field using subwavelength cavity arrays in the near-infrared

Abstract

A frequency selective metasurface capable of sorting photons in the near-infrared spectral range is designed, fabricated, and characterized. The metasurface, a periodic array of dielectric cylindrical cavities in a gold film, localizes and transmits light of two spectral frequency bands into spatially separated cavities, resulting in near-field light splitting. The design and fabrication methodologies of the metasurface are discussed. The transmittance and photon sorting properties of the designed structure is simulated numerically and the measured transmission is presented.

Nearly perfect absorption in a single-layer metallic grating with rectangular grooves on its front surface

“…It is well known that metallic gratings, especially the compound metallic grating are rich in all kinds of resonances which include the horizontal surface plasmons (HSPs) [10,11], cavity modes (CMs) [10,11], Wood-Rayleigh (WR) anomalies [12], phase resonance (PR) [13,14] and various coupled resonant modes between them. These resonances make it possible to manipulate the light in near field, such as enhanced or inhibited transmission [11,15], photon sorting [16,17], light trapping [18], light concentration and enhanced absorption [17,18]. As for the perfect absorption, various designs of grating structures have been proposed in the previous literatures, such as crossed gratings [19], a lamer grating with metallic substrate [20], a cylindrical cavity grating [21], a three-layer tungsten grating structure [22] and other three-layer compound metallic gratings [23,24].…”

Light harvesting with metasurfaces: applications to sensors and energy generation

“…A second application is for renewable energy applications where the incoming solar radiation is split according to wavelength, and the different energy photons are channeled to different absorbers that collect the light and transfer the optical energy to electrical energy; this structure avoids the ''thermalization losses'' inherent in single-junction silicon solar cells. With the devices developed in our works [21,22], we aimed to have the engineered surfaces perform three functions: photon sorting, light localization, and absorption. Additionally, the devices were designed to perform these functions on incident light of any polarization and over a wide range of angles of incidence.…”

“…Even though this particular structure was designed to operate in the microwave spectral region, the underlying principles can be applied to SAA that operate in other spectral regions [21]. To do this, one scales the geometric Fig.…”

“…In the IR, multiband IR detectors can be designed, whereas in the visible and near-IR spectral regions, multi-junction solar cells can be developed. To demonstrate this concept in the IR, we described in [21] the design, fabrication, and testing of IR photon sorting metasurface of a very similar design as the microwave structure shown in Fig. 1, but with the structural feature sizes scaled down considerably: K = 500 nm, a 1 = 80 nm, a 2 = 125 nm, h = 35 nm, and with the metal being gold (with the complex permittivity provided by Palik [24]) and amorphous silicon (a-Si) filling the cavities, as shown in Fig.…”

Control of the diffracted response of a metallic wire array with double period: experimental demonstration

“…For instance, a double-period diffraction grating attached to a photonic crystal allows a directional control of the propagating waves, which makes it work like an optical diode [1]. Dual-period dielectric gratings have also been proposed to control the optical response in nanoantennas [2][3][4][5] and to introduce significant changes in the reflected and transmitted response of regular periodic structures [6][7][8][9][10][11][12][13].…”