Design Of Micro-Nano Optical Waveguide Devices Based On Subwavelength

With the advent of the information technology era,various functional devices are becoming more and more important in the fields of information transmission and processing,and people have increasingly strict requirements on the performance and integration of devices.At present,the development of integrated circuits is difficult to break through the physical limits and is restricted by factors such as insufficient bandwidth,signal delay and thermal noise,leading to the existence of "electronic bottleneck".As an emerging field of information transmission,integrated photonic chip has the advantages of large bandwidth,miniaturization and high reliability,and may become one of the key technologies to solve this problem.Among them,the subwavelength optical waveguide structure shows potential application value in size matching and breaking through the diffraction limit,and it plays an important role in the integration of new micro-nano photonic chips.Therefore,micro-nano optical waveguide devices based on subwavelength are studied and analyzed in this paper.The main research work is as follows:Firstly,the numerical calculation methods of sub-wavelength micro-nano optical waveguide devices are reviewed.By comparing various research methods,the rigorous coupled wave analysis method is selected,and the sub-wavelength grating structure is simulated and analyzed with the help of Rsoft software.In addition,for sub-wavelength micro-nano metal structures,finite-difference time-domain(FDTD)method is one of the most commonly used and effective theoretical calculation methods.In order to further improve the computational efficiency and accuracy,the commercial software FDTD Solutions is used as the modeling tool for this type of structure.Secondly,based on sub-wavelength Guided-mode Resonance(GMR)grating,the structure of the cascade dual GMR gratings filter and the ultra-narrow band filter based on the subwavelength is studied and analyzed by Rsoft software modeling and simulation.The former is a rectangular spectral filter,using a new triple cascade flat-top narrowband bandpass filter structure.The simulation results show that the structure effectively achieves a nearly rectangular transmission spectrum with a full width at half maximum of about 0.3nm near the wavelength of 1550 nm.The latter is based on the sub-wavelength ultra-narrow band filter design,using two single GMR grating structures in series.The grating is divided into two structures: without air gap and with 2.13?m interval air layer.The simulation results show that the peak transmittance of the double GMR grating series structure without air gap is about100%,and the FWHM can reach 0.012 nm at the wavelength of 1550nm;The transmission and FWHM of the double GMR grating series structure with air gap are about 100% and 0.15 nm,and the flat top filtering curve is obtained,and the flatness is about 0.1d B.Finally,in order to realize the sensor detection of wireless transmission demodulation,the butterfly metal nanoarray structure refractive index sensor and the plasma modulator are designed by using FDTD Solutions software.The structural model of the sensor is numerically calculated and the structural parameters are optimized.The sensitivity is 990nm/RIU,the figure of merit can reach 16.5.The vertical step metal grating coupler,polarization converter and MZI modulated waveguide configured in the plasma modulator are preliminarily designed.The optical simulation shows that the coupling efficiency of the coupler is above 58.09% in the wavelength range of 1525nm-1565 nm,and the MZI modulated waveguide slit has a good binding effect on the energy of the light field.