A new photonics biosensor configuration comprising a Double-side Ring Add-drop Filter microring resonator (DR-ADF) made from SiO₂-TiO₂ material is proposed for the detection of Salmonella bacteria (SB) in blood. The scattering matrix method using inductive calculation is used to determine the output signal’s intensities in the blood with and without presence of Salmonella. The change in refractive index due to the reaction of Salmonella bacteria with its applied antibody on the flagellin layer loaded on the sensing and detecting microresonator causes the increase in through and dropper port’s intensities of the output signal which leads to the detection of SB in blood. A shift in the output signal wavelength is observed with resolution of 0.01 nm. The change in intensity and shift in wavelength is analyzed with respect to the change in the refractive index which contributes toward achieving an ultra-high sensitivity of 95,500 nm/RIU which is almost two orders higher than that of reported from single ring sensors and the limit of detection is in the order of 1 × 10⁻⁸ RIU. In applications, such a system can be employed for a high sensitive and fast detection of bacteria.

The novel twisted ring resonator called add-drop Mobius microring resonator is introduced and modelled with the analytical solution of transfer matrix methods for the generation of optical bistability. Simulated results show that, the add-drop Mobius configuration provides greater phase shift due to the longer length of propagation per roundtrip than add-drop filter configuration. In add-drop Mobius system, drop port generated the optical bistable hysteresis loop with 19.25 mW output switching power and through port generated lower switching power as 5.55 mW. The drop port of the system is found as the suitable port for the operating the all-optical hysteresis switching.

Unique configuration of integrated ring resonator circuit were modeled and discussed in this paper. The system consisted series of sub-micron size ring resonators fabricated by using nonlinear InGaAsP/InP material that laterally coupled together. This particular configuration is known as double PANDA ring resonator. For convenience of analysis, optical transfer function for this model is obtained by using Z-transform method. Equations governing pulse propagation within the system including output and circulated fields are discussed in details. Simulation results were based on analytical derivation. It suggested that intensity buildup is induced by the additional nanorings located ad both left and right sides of the system. This study mainly contribute towards the establishment of mathematical model of such system that able to predict accurately the practical operation processes of double PANDA ring resonator configuration.