Optical module testing ensures stable performance, reliability through power measurement, BER testing, aging tests, and inspection. The working principle of optical modules is illustrated in the diagram shown in the Optical Module Working Principle Diagram. This. The Transmitter Optical Sub Assembly (TOSA) is responsible for the emission of light. Its primary function entails converting electrical signals into optical signals. It measures parameters such as wavelength (in nanometers or nanometers), optical power (in dBm), and signal-to-noise ratio (SNR), providing a. Optical module testing plays a vital role in modern optical communication systems.