提出了一种以金刚石新型材料为芯层的单微环谐振器模型.谐振器的纵切面采用五层脊形波导结构,中间一层设定为金刚石,上下两侧分别是SiO2和As2S3,即As2S3-SiO2-金刚石-SiO2-As2S3.设置操作波长为1550 nm,依据耦合膜理论和微环谐振理论,利用Comsol软件仿真模拟了单直波导纵切面、直波导和环形波导耦合区的纵切面以及微环在谐振波长为1543 nm时的场强分布,及直波导和环形波导耦合区间距改变时微环的场强分布和传输特性.在此基础上,依据传输矩阵法讨论了微环的品质因数、耦合系数变化对输出光谱的影响,并对微环损耗进行了讨论.结果表明:以金刚石为芯层的微环谐振器具有良好的光学特性,本结构在谐振波长为1543 nm时谐振峰值达到了-12 dB以上,品质因数达到了1.54×105,在耦合系数为0.01时,自由光谱范围约为40 nm.%With the development of the technology for fabricating high-quality synthetic diamond and diamond waveguide structures, more and more researchers are being involved in exploring the particular optical properties of diamond for different applications. Because of its high refractive index and nontoxicity to biological species, diamond can be used to make micro-ring resonator to detect the concentration of liquid or gas. In this paper, a single micro-ring resonator model with diamond serving as the core layer is proposed. In the model, the vertical-section of the waveguide adopts a five-layer ridge-type waveguide structure based on As2S3, SiO2 and diamond, i.e. As2S3-SiO2-Diamond-SiO2-As2S3. To investigate the optical properties of the resonator, the vertical-section of the single straight waveguide, the coupling region of the direct waveguide, and the ring waveguide are simulated with the adopted operating wavelengthλ=1550 nm based on the coupling mode theory and micro-ring resonance theory. In addition, the distribution of the field strength for the micro-ring is described at a resonant wavelength of 1543 nm. It is very important to explore the field intensity distribution of the micro-ring for understanding how the light transmits. The transmission characteristics of the micro-ring with the change of the distance between the straight waveguide and the ring waveguide in the coupling region are also simulated. The quality factor and the influence of the coupling coefficient change on the output spectrum are studied by the transfer matrix method and the micro-ring loss is discussed. It is shown that the micro-ring resonator designed with the diamond material has good transmission characteristics. When the resonant wavelength is 1543 nm, the resonant peak reaches more than-12 dB. The quality factor is about 1.54 × 105. When the coupling coefficient k is 0.01, the free spectral range is about 40 nm. The coupling coefficient k is determined by the distance S of the coupling region. The results show that when S is equal to 50 nm, the output spectrum has a good extinction ratio and is better compared with the other values. The error of material processing is mainly affected by size, so the output spectrum near the distance S =50 nm is studied. The result shows that in the tiny change scope, the spectral output peak is linearly related to S. The structure we suggested in this paper expands the application scope of diamond in the field of optics, and provides some guiding significance for developing the optical integrated chips.
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