We propose a metal-vanadium dioxide (VO2) metamaterial with broadband and functionality-switchable polarization conversion in the terahertz regime. Simulation results show that function of proposed can be switched from half-wave plate (HWP) to quarter-wave (QWP) over broad bandwidth 0.66-1.40 THz, corresponding relative 71.8%. The HWP obtained when VO2 is insulating state has reflection 90% linear ratio exceeding 98% 0.58-1.40 THz. By transiting phase into conducting state, QWP convert...

We propose a nonvolatile, reconfigurable, and narrowband mid-infrared bandpass filter based on surface lattice resonance in phase-change material Ge2Sb2Te5. The proposed is composed of two-dimensional gold nanorod array embedded thick Ge2Sb2Te5 film. Results show that when transits from the amorphous state to crystalline state, reflection spectrum tuned 3.197 μm 4.795 μm, covering majority regime, peak reflectance decreases 72.6% 25.8%, corresponding quality factor 19.6 10.3. spectral tuning...

The Raman spectra of tissue 20 brain tumor patients was recorded using a confocal microlaser spectroscope with 785 nm excitation in vitro. A total 133 were investigated. Spectra peaks from normal white matter and analyzed. Algorithms, such as principal component analysis, linear discriminant the support vector machine, are commonly used to analyze spectral data. However, this study, we employed learning quantization (LVQ) neural network, which is typically for pattern recognition. By...

We propose a novel configuration for nonvolatile and reconfigurable tuning of surface lattice resonances (SLRs) based on thin films phase-change material Ge2Sb2Te5 (GST). The is composed gold nanorod array embedded in GST film. Results show that, an extremely wide SLR wavelength range reaching 1600 nm, large figure merit 21, high quality factors 47 17 can be achieved the mid-infrared regime when transits from amorphous state into crystalline state. effects layer thicknesses performance are...

We report the design of broadband highly reflective subwavelength high-index-contrast gratings (HCGs) for both TE and TM polarizations in visible regime. Results show that high reflectivity above 99% covering 544–726 nm or 510–666 can be achieved, corresponding to a fractional bandwidth Δ λ / 0 = 28.7% 26.5% polarization, respectively. reveal these broad high-reflectivity bands originate from blend multiple leaky modes, similar counterparts operating near-infrared By investigating effects...

Here we report a tunable polarization-independent broadband absorber in the terahertz regime. The proposed structure consists of periodic all-dielectric array on gold substrate, sandwiched by monolayer graphene and an epsilon-near-zero layer. Simulation results show that absorption is independent from incident polarization remains above 90% over spectral range 1.6 THz to 4.1 THz, corresponding bandwidth 2.5 relative 87.7%. By varying graphenes Fermi energy 0.2 eV 0.5 eV, can be turned 1.5...

We report the design an ultra-broadband highly reflective subwavelength grating that covers almost entire visible region. Results show high reflectivity above 90% covering 450–700 nm can be achieved, corresponding to Δλ/λ=43%. also provide intuitive physical insights into broadband reflection performance of reflector. expect this ultra-thin, and all-dielectric reflector find applications in hyperspectral imaging based on tunable etalon filters.

We propose a nonvolatile, reconfigurable, and narrowband mid-infrared bandpass filter based on surface lattice resonance in phase-change material Ge2Sb2Te5 (GST). The proposed is composed of two-dimensional gold nanorod array embedded thick GST film. Results show that when transits from the amorphous state to crystalline state, reflection spectrum tuned 3.197 {\mu}m 4.795 {\mu}m, covering majority regime, peak reflectance decreases 72.6% 25.8%, corresponding Q-factor 19.6 10.3. spectral...