Fig. 1. Schematic diagram and transmission spectrum: (a) MDM waveguide coupled square cavity structure with F-P cavity;(b) transmission spectrum; (c) phase diagram.结构示意图和透射光谱图　(a)含F-P腔的MDM波导耦合方形腔结构；(b)透射光谱；(c)相位图

Fig. 2. The H_z field distribution: (a) The H_z field distribution at the peak of FR1; (b) the H_z field distribution at the dip of FR1; (c) the H_z field distribution at the peak of FR2; (d) the H_z field distribution at the dip of FR2. H_z场分布　(a) FR1波峰处的H_z场分布；(b) FR1波谷处的H_z场分布；(c) FR2波峰处的H_z场分布；(d) FR2波谷处的H_z场分布

Fig. 3. Influence of parameters l₁ and l₂ on sensing characteristics: (a) Influence of parameters l₁ on the FR1; (b) influence of parameters l₂ on the FR2; (c) influence of parameters l₁ = l₂ or l₁/l₂ on the Fano resonance. 参数l₁和l₂对传感特性的影响　(a)参数l₁对FR1的影响；(b)参数l₂对FR2的影响；(c)参数l₁ = l₂或l₁/l₂对Fano共振线型的影响

Fig. 4. Influence of parameters L₁ on sensing characteristics: (a) Influence of parameters L₁ on the FR1; (b) influence of parameters L₁ on the FOM value of FR1; (c) influence of parameters L₁ on the FR2; (d) influence of parameters L₁ on the FOM value of FR2. 参数L₁对传感特性的影响　(a)参数L₁对FR1的影响；(b)参数L₁对FR1的FOM值的影响；(c)参数L₁对FR2的影响；(b)参数L₁对FR2的FOM值的影响

Fig. 5. Influence of parameters g₁, g₂ and refractive index n₁,n₂ on sensing characteristics: (a) Influence of parameters g₁ on the FR1; (b) influence of parameters g₂ on the FR2; (c) influence of refractive index n₁ on the FR1; (d) influence of refractive index n₂ on the FR2. 参数g₁, g₂和折射率n₁, n₂对传感特性的影响　(a)参数g₁对FR1的影响；(b)参数g₂对FR2的影响；(c)折射率n₁对FR1的影响；(d)折射率n₂对FR2的影响