Tunable mid-wave infrared Fabry-Perot bandpass filters using phase-change GeSbTe

Nonvolatile, reconfigurable and narrowband mid-infrared filter based on surface lattice resonance in phase-change GeSbTe

We propose a nonvolatile, reconfigurable, and narrowband mid-infrared bandpass filter based on surface lattice resonance in phase-change material Ge2Sb2Te5 (GST). The proposed filter is composed of a two-dimensional gold nanorod array embedded in a thick GST film. Results show that when GST transits from the amorphous state to the crystalline state, the narrowband reflection spectrum of the proposed filter is tuned from 3.197 μm to 4.795 μm, covering the majority of the mid-infrared regime, the peak reflectance decreases from 72.6% to 25.8%, and the corresponding Q-factor decreases from 19.6 t…

基于双层亚波长金属杆的可机械重构太赫兹带通滤波器

Mechanically Reconfigurable Terahertz Bandpass Filter Based on Double-Layered Subwavelength Metallic Rods

本文提出一种可机械重构的双层亚波长金属结构，用于可变频太赫兹传输带通滤波。通过调节垂直层间间距，实现频率调节，具有高传输效率和宽调谐范围。

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

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 (Δλ/λ = 16%). The center wavelengths of each filter are independe…

Bandwidth tunable optical filter based on a tri-mode high-contrast grating

We propose a monolithic optical bandpass filter with a transmission bandwidth tunable by the incident angle in a tri-mode high-contrast grating (HCG). We attribute this extraordinary phenomenon to the destructive interference between the TM$_{0}$ and TM$_{2}$ modes and the Fabry-Pérot resonance of the TM1 mode, which can only be excited at the oblique incidence. The transmission bandwidth can be tuned from zero at normal incidence and increases quadratically with incident angle, while the center wavelength reds shifts slightly. The corresponding Q factor can be continuously tuned from 10$^{6}$…