Dual-function splitting of the embedded grating with connecting layer

2019 ◽  
Vol 33 (11) ◽  
pp. 1850129
Author(s):  
Wenhua Zhu ◽  
Bo Wang ◽  
Chenhao Gao ◽  
Kunhua Wen ◽  
Ziming Meng ◽  
...  
Keyword(s):  
Transverse Electric ◽  
Groove Depth ◽  
Transverse Magnetic ◽  
Dual Function ◽  
First Order ◽  
Rigorous Coupled Wave Analysis ◽  
Rigorous Coupled Wave ◽  
Plane Light ◽  
High Diffraction ◽  
Modal Method

We design and optimize the embedded dual-function grating with connecting layer in Littrow mounting. By using modal method and rigorous coupled-wave analysis, grating parameters are analyzed and calculated including grating groove depth, thickness of connecting layer, and so on. The grating device can diffract the transverse electric-polarized plane light mainly in the first-diffractive order with high-diffraction efficiency of 98.36%. Meanwhile, for the transverse magnetic-polarized plane light, the diffraction efficiencies in the zeroth-order and the first-order corresponding to 49.34% and 49.29% are obtained, respectively.

SURFACE-COVERED 1×3 GRATING WITH DIELECTRIC-METAL SLABS UNDER SECOND BRAGG INCIDENCE

2020 ◽  
Vol 27 (09) ◽  
pp. 1950201
Author(s):  
CHEN FU ◽  
BO WANG ◽  
WENHUA ZHU ◽  
KUNHUA WEN ◽  
ZIMING MENG ◽  
...  
Keyword(s):  
Incident Light ◽  
Polarized Light ◽  
Transverse Magnetic ◽  
Second Order ◽  
Bragg Angle ◽  
Efficiency Ratio ◽  
First Order ◽  
Rigorous Coupled Wave Analysis ◽  
Rigorous Coupled Wave ◽  
The Given

This paper designed a novel three-port reflective surface-covered grating with a connecting layer. The grating can be used as a splitter, and the polarized light can be divided into zero order, first order and second order. Through rigorous coupled-wave analysis, the efficiency of the three orders of diffraction light is close to 33% under the condition that the incident light at 1550 nm is incident at the second Bragg angle and the given duty cycle is 0.5. The efficiency and bandwidth of the surface-covered grating are improved compared with that of the surface-relief grating reported in the past. Especially for transverse magnetic polarized light, the beam splitting effect is more uniform, the efficiency ratio of the zeroth order to first order can reach 1.01, and the efficiency ratio of the first order to second order can reach 1.

Reflective three-port high-efficiency grating with two dielectric layers based on a sandwiched configuration

2016 ◽  
Vol 30 (12) ◽  
pp. 1650072 ◽  
Author(s):  
Hongtao Li ◽  
Bo Wang ◽  
Hao Pei ◽  
Wenhao Shu ◽  
Li Chen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Transverse Electric ◽  
Transverse Magnetic ◽  
Wave Analysis ◽  
Beam Splitting ◽  
Practical Applications ◽  
Rigorous Coupled Wave Analysis ◽  
Dielectric Layers ◽  
Rigorous Coupled Wave ◽  
Sandwiched Structure

In this paper, we describe a novel reflective sandwiched three-port grating with two dielectric layers. The two-layer sandwiched grating can separate incident wave into the [Formula: see text] and the 0th-order with high-efficiency beam splitting and good splitting ratios for both transverse electric (TE) and transverse magnetic (TM) polarizations. The grating parameters can be optimized by using rigorous coupled-wave analysis (RCWA) with a special duty cycle of 0.6. With the optimized results, efficiencies more than 32% in the [Formula: see text]st-orders and the 0th-order can be obtained. Furthermore, performance of the incident bandwidth and aspect ratio can be improved. Compared with conventional surface-relief grating, the grating with sandwiched structure is aimed at cleaning and protecting grating surface. The presented reflective two-layer sandwiched three-port grating would be put into practical applications for its beneficial performances.

Study of the Absorptance of Si-gratings and of arrays of SiO2-filled trenches on Si-grating substrate

2016 ◽  
Vol 12 (2) ◽  
pp. 4278-4290
Author(s):  
Faouzi Ghmari ◽  
Ilhem Mezni
Keyword(s):  
Transverse Electric ◽  
Transverse Magnetic ◽  
Radiative Properties ◽  
Geometrical Parameters ◽  
Perfect Absorber ◽  
Angle Of Incidence ◽  
Patterned Wafers ◽  
Rigorous Coupled Wave Analysis ◽  
Rigorous Coupled Wave ◽  
Model Structures

The purpose of this paper is to study the radiative properties of two model structures. The first model (A-1) is a rectangular grating of silicon (Si). The second one (A-2) is obtained from A-1 by filling their trenches by SiO2. These patterned wafers are characterized by three geometrical parameters, the period d, the filling factorand the thickness h. To derive and compute the radiative properties we use a rigorous coupled wave analysis (RCWA) method. Our attention is focused on the absorptance of these structures when they are illuminated by a monochromatic plane wave. We investigate the effect of the filling factor on the absorptance versus the direction of the incident wave. At specific angles of incidence the effect of the period is also studied. Besides, the influence of the thickness h on the absorptance is included throughout this work. At the wavelength = 632,8nm, we especially show that we can identify several perfect absorber model structures characterized by specific parameters and by accurate angle of incidence. We show that this will be done in both transverse electric (TE) and transverse magnetic (TM) polarization cases.

Research of High Performance Polarization-Independent Grating Beam Splitter

2013 ◽  
Vol 310 ◽  
pp. 481-485
Author(s):  
Ke Zhao ◽  
Xiao Min Lei ◽  
Guo Feng Xie ◽  
Wen Hua Xiong
Keyword(s):  
High Performance ◽  
Beam Splitter ◽  
Transverse Electric ◽  
Transverse Magnetic ◽  
Silicon On Insulator ◽  
Material System ◽  
Design And Optimization ◽  
Rigorous Coupled Wave Analysis ◽  
Rigorous Coupled Wave ◽  
Polarization Independent

Based on a silicon-on-insulator (Silicon-on-insulator, SOI) material system design and optimization of a high performance, the polarization independent of 1 × 3 subwavelength grating stars beam splitter. By a rigorous coupled-wave analysis method showed that, in the 1550nm wavelength range, at vertical incidence, the device on the transverse electric field (transverse electric, TE) ,the 0 and ± 1 order transmittance is 31%, 32%, 32%,respectively; cross the magnetic field (transverse magnetic, TM), the 0 and ± 1 transmittance is 33%, 32%, 32%, respectively.

Reflection performance research of grating with polarization independence based on a sandwiched structure

2018 ◽  
Vol 32 (04) ◽  
pp. 1850042
Author(s):  
Hao Pei ◽  
Bo Wang ◽  
Wenhua Zhu ◽  
Sufang Yin ◽  
Li Chen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Optical Element ◽  
The Novel ◽  
First Order ◽  
Rigorous Coupled Wave Analysis ◽  
Rigorous Coupled Wave ◽  
Sandwiched Structure ◽  
The Given ◽  
Performance Research ◽  
Modal Method

The novel reflective grating was studied under Littrow incidence as one sort of high-efficiency optical element. A covering layer and a dielectric layer are employed in this structure to achieve higher efficiency and wider bandwidth. For the given wavelength of 1550 nm, by using two-beam-interference theory of modal method, duty cycle and period of grating can be calculated, where the physical essence of high efficiency in the first-order is well explained by the modal method. The other grating parameters are optimized by using rigorous coupled-wave analysis. The optimized grating has an appropriate aspect ratio and shows that diffraction efficiencies of TE and TM polarizations in the first-order are greater than 97%. Compared with the reported surface-relief high-efficiency grating, the diffraction efficiencies of the proposed grating for TE and TM polarizations can be greatly improved.

SURFACE-RELIEF THREE-PORT OUTPUT WITH A CONNECTING LAYER GRATING UNDER THE SECOND BRAGG CONDITION

2019 ◽  
Vol 26 (02) ◽  
pp. 1850140 ◽  
Author(s):  
BO WANG ◽  
WENHUA ZHU ◽  
HONGTAO LI ◽  
SUFANG YIN ◽  
CHENGYUE SU ◽  
...  
Keyword(s):  
Surface Relief ◽  
Polarized Light ◽  
Grating Period ◽  
Fused Silica ◽  
The Novel ◽  
Bragg Condition ◽  
Rigorous Coupled Wave Analysis ◽  
Different Depths ◽  
Rigorous Coupled Wave ◽  
Modal Method

A three-port surface-relief grating with a connecting layer under the second Bragg condition is put forward and designed for the free space application in this paper. Such grating can function as a beam splitter, which can split the polarized light into the [Formula: see text]2nd order and the [Formula: see text]1st order and the 0th order based on the optimum grating profile parameters. By using rigorous coupled-wave analysis, a highly-efficient polarization-dependent connecting-layer-based grating can be obtained with the optimum different depths and thicknesses with the grating duty cycle of 0.65 and grating period of 1150[Formula: see text]nm. On the basis of the designed grating profile parameters, a modal method can explain the propagating process. Compared with the conventional surface-relief fused-silica grating, the diffraction efficiencies for TE polarization in three orders are improved. Therefore, the novel conception of the grating under the second Bragg condition is significant for further applications such as interferometer with improved efficiency for TE polarization.

Impacts of Nanoscale Features on Infrared Radiative Properties of Metallic Slit Arrays

2009 ◽  
Author(s):  
Y.-B. Chen ◽  
J.-S. Chen ◽  
P.-F. Hsu
Keyword(s):  
Transverse Magnetic ◽  
Radiative Properties ◽  
Cavity Resonance ◽  
Resonance Excitation ◽  
Angle Of Incidence ◽  
Resonance Modes ◽  
Rigorous Coupled Wave Analysis ◽  
Rigorous Coupled Wave ◽  
Nanoscale Features ◽  
Poynting Vectors

Radiative properties (absorptance, reflectance, and transmittance) of deep slits with five nanoscale slit profile variations at the transverse magnetic wave incidence are numerically investigated in this work by employing the rigorous coupled-wave analysis. For slits with attached features, their radiative properties can be much different due to the modified cavity geometry and dangled structures, even at wavelengths between 3 and 15 μm. The shifts of cavity resonance excitation result in higher transmittance through narrower slits at specific wavelengths and resonance modes are confirmed with the electromagnetic fields. Opposite roles possibly played by features in increasing or decreasing absorptance are determined by the feature position and demonstrated by Poynting vectors. Correlations among all properties of a representative slit array, the angle of incidence, and the slit density are also comprehensively studied.

Modes simulation and numerical optimization of encapsulated connecting-layer grating for high efficiency

2018 ◽  
Vol 32 (31) ◽  
pp. 1850386 ◽  
Author(s):  
Chenhao Gao ◽  
Bo Wang ◽  
Hongtao Li ◽  
Kunhua Wen ◽  
Ziming Meng ◽  
...  
Keyword(s):  
Numerical Optimization ◽  
High Efficiency ◽  
Photonic Devices ◽  
The Novel ◽  
Wave Analysis ◽  
Rigorous Coupled Wave Analysis ◽  
Rigorous Coupled Wave ◽  
Polarization Independent ◽  
Modal Method ◽  
Coupled Wave

We propose and investigate a polarization-independent high-efficiency encapsulated subwavelength grating with a connecting layer in this paper. Numerical simulated method of rigorous coupled-wave analysis is adopted for optimization. Based on the simulated precise results, a simplified modal method is used to give perspicuous physical propagating fundamentals and explain wideband performance in the grating, where the coupled efficiencies by means of the simplified modal method are to be in conformity with the calculated values of the rigorous coupled-wave analysis for TE and TM polarizations. Compared with the researched surface-relief polarization-independent single-port grating, efficiencies are improved with 98.1% for TE polarization and 98.2% for TM polarization. Hence, the novel gratings with some superiorities are suitable for promising photonic devices.

Spectral Features of an Omnidirectional Narrowband Emitter

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Yutao Zhang ◽  
Yimin Xuan
Keyword(s):  
Incident Angle ◽  
Structural Parameters ◽  
Infrared Region ◽  
Transverse Magnetic ◽  
Silver Layer ◽  
Spectral Features ◽  
Structured Surface ◽  
Rigorous Coupled Wave Analysis ◽  
Spectral Emittance ◽  
Rigorous Coupled Wave

A microscale-structured surface consisting of heavily doped silicon rectangle grating and slotted silver layer is studied for omnidirectional narrowband emitter. Numerical simulation is implemented to obtain spectral emittance in mid-infrared region (6–16 μm) for the transverse magnetic incidence by using the rigorous coupled-wave analysis (RCWA) method. The effects of structural parameters and incident angle on its spectral emittance are investigated. In virtue of the microcavity effect, an omnidirectional narrowband emitter is proposed. By selecting a group of structural parameters, its peak emittance reaches as high as 0.998, and the peak width Δλ/λ of the emittance peak is as narrow as 0.03 at the specified wavelength. The results reveal that our proposed structured surface has the nice spectral features of angular uniformity and wavelength-selective characteristic, which can be applied to design novel narrowband thermal emitters and detectors in the infrared region.

Sign in / Sign up

Export Citation Format

Share Document