Fast controllable optical passive devices containing intricate couplings of multiple physical fields, for instance, magneto-, electro-, and acousto-optic interactions, are frequently used as critical regulation tools in diverse optical systems. Silicon photonics has emerged as a critical enabling technology for a diverse range of applications, from high-speed data communication and computing to advanced sensing and quantum information processing. This paper provides a comprehensive review of recent progress in the foundational passive. A novel technique can be used to make high-resolution, wide-band, and high-speed measurements of amplitude, phase response, and polarization. Optical spectrum analyzers (OSAs) use monochromators to transmit a specific range of light wavelengths. Conventional grating-based OSAs, however, have slow. This paper presents a novel interferometric fiber optic gyroscope (IFOG) architecture, the Double-Sensitive Non-Reciprocal Polarization Phase Shifter IFOG (DS-NRPPS-IFOG), which introduces—for the first time—a fully passive phase biasing scheme capable of simultaneous operation at two quadrature. Optics engineering focuses on transmitting data using light, a method providing the high speeds and vast bandwidth necessary for modern digital life. Passive optical components play a fundamental role within this infrastructure. Their unpredictable transient spectral properties. Optical Passive Device Market size was valued at US$ 8. 23 billion in 2024 and is projected to reach US$ 14.