Optical module PCB technology is evolving rapidly to meet the extreme demands of AI data centers and high‑speed networks. 6T, next‑generation optical modules require higher density, advanced materials, innovative thermal management, and new architectures such as CPO. The optical module serves as a crucial component in optical fiber communication systems, operating at the physical layer, which is the lowest layer in the OSI model. Its primary function is to achieve optoelectronic conversion by converting electrical signals into optical signals and vice versa. Optical modules typically have an electrical interface on the side that connects to the inside of the system and an optical interface on the side that connects to the outside. The Marvell network switch with a co-packaged optics (CPO) module that includes photonic engines around the perimeter of switch application-specific integrated circuit (ASIC) and detachable fiber optic connectors. ELSFP: external laser small form-factor pluggable. This article. This comprehensive guide will explore optical chips, their types, applications, their impact on optical module performance, and the exciting future trends in optical chip technology. These two types work hand in hand to.