Wide bandwidth and high resolution planar filter array based on DBR-metasurface-DBR structures

Abstract

Abstract:We propose and experimentally demonstrate a planar array of optical bandpass filters composed of low loss dielectric metasurface layers sandwiched between two distributed Bragg reflectors (DBRs). The two DBRs form a Fabry-Pérot resonator whose center wavelength is controlled by the design of the transmissive metasurface layer which functions as a phase shifting element. We demonstrate an array of bandpass filters with spatially varying center wavelengths covering a wide range of operation wavelengths of 250 nm around λ = 1550 nm (∆λ /λ = 16%). The center wavelengths of each filter are independently controlled only by changing the in-plane geometry of the sandwiched metasurfaces, and the experimentally measured quality factors are larger than 700. The demonstrated filter array can be directly integrated on top of photodetector arrays to realize on-chip high-resolution spectrometers with free-space coupling. 13, 139-150 (2014). 14. S. Jahani and Z. Jacob, "All-dielectric metamaterials," Nat. Nanotechnol. 11, 23-36 (2016) 10, 937-943 (2015).

A review of dielectric optical metasurfaces for wavefront control

“…We should note here that the applications of optical metasurfaces in the general sense of the word (i.e., patterned thin layers on a substrate) go beyond spatial wavefront manipulation. Thin light absorbers [79][80][81][82][83][84][85][86][87][88][89][90][91][92][93], optical filters [94][95][96][97][98][99][100][101][102][103][104][105][106], nonlinear [107][108][109][110][111][112][113][114], and anapole metasurfaces [115,116] are a few examples of such elements. This review is focused on applications of metasurfaces in wavefront manipulation, and therefore it doesn't cover these other types of metasurfaces.…”

Compact folded metasurface spectrometer

“…As a result, various schemes and structures have been investigated for realization of such spectrometers [7][8][9][10][11][12][13][14][15][16]. One class of miniaturized spectrometers integrate a series of band-pass filters with different center wavelengths on an array of photodetectors [8,17]. Although these devices are compact and compatible with standard microfabrication techniques, they have resolutions limited by achievable filter quality factors, and low sensitivities caused by the filtering operation that rejects a large portion of the input power.…”

Nanostructure-modulated planar high spectral resolution spectro-polarimeter

“…The most common approach to tailor the transmission is to change the physical length of the cavity L 0 [25]. However, it has been recently demonstrated that inclusions, such as arrays of high-index nanostructures, might be used to modulate the effective index n eff [14]. The inclusion of high-index nanostructures adds a phase shift to the cavity and a subsequent red-shift of the resonant peak, see Fig.…”

“…A metasurface is a two-dimensional nanostructure array, which enables control of amplitude, phase, and polarization of the incident light [7]. It has been successfully used in the realizations of polarimeters [8][9][10][11][12], spectral filters and spectrometers [13][14][15][16][17][18], and even spectro-polarimeters [19][20][21][22]. However, there are still several obstacles to overcome and challenges to be addressed.…”