What is the purpose of using a launch cable during testing of fiber optics?

Using a launch cable during the testing of fiber optics serves to create a stable light source for accurate measurements. This ensures that the testing equipment receives a consistent and well-defined signal as it tests the performance and integrity of the fiber optic link. The launch cable allows the measurement of the system’s performance by facilitating a specific length of fiber that can help minimize the effects of connector loss and splicing losses.

By incorporating a launch cable, technicians can achieve reliable readings of the fiber's characteristics, such as attenuation, insertion loss, and overall link performance. This setup is particularly useful when simulating real-world conditions that the fiber will experience once it is installed, allowing for more precise diagnostic capabilities and performance verification. Thus, the launch cable plays a crucial role in ensuring that the testing performed is reflective of the actual operational conditions of the fiber optic installation.