The main aim of this paper is to review the standardization evolution of PON to next generation passive optical network (NG-PON). 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. Passive optical network (PON) is a developed and most encouraging access network which provides the high bandwidth, information rate and low cost architecture for home and business enterprises. 4 billion in 2025 and is projected to grow at a CAGR of 11. This expansion is fueled by rising demand across industrial, commercial, and technology-driven applications, alongside continuous innovation. Benefiting from high receiver sensitivity, expanded modulation dimensions, and wavelength selectivity, coherent optics is emerging as a promising solution for next-generation 200G or even 400G optical access networks. Accordingly, coherent PON has been included by ITU-T Q2/SG15 as a candidate. Market Size, By Component (Optical Splitters & Couplers, Wavelength Division Multiplexers (WDM), Optical Filters, Optical Isolators, Optical Circulators, Fiber Bragg Gratings (FBG), Optical Attenuators, Optical Connectors, Optical Adapters, Others), By Packaging (Discrete Passive Components.