Silicon Photonics Sensors for Biophotonic Applications—A Review

In the last two decades, biosensors have made a remarkable development in the area of food quality monitoring, drug discovery, environmental monitoring, soil quality monitoring, the healthcare industry, and medical point of care diagnosis. The integrated silicon photonic-based biosensors using the evanescent wave (EW) field and their advantages in terms of high sensitivity, high reliability, compactness, robustness, and miniaturization are discussed in this review. Specifically, different silicon photonic device configurations based on the EW field, such as interferometer-, resonator-, photonic crystal-, and Bragg grating-based biosensors, are discussed in detail. Moreover, various performance improvement strategies, such as advance and fundamental approaches, including Vernier effect-based systems in the cascaded form of the Mach–Zehnder interferometer (MZI)-ring resonator, are also reviewed. This article further reviews the usage of silicon-photonic biosensors for lab-on-chip (LOC) applications, including optoelectronic integrated circuits (OEICs). The state-of-the-art performance of different biosensors technologies is also comparatively discussed.