It refers to the amount of signal power lost when the switch is introduced into the optical path. Measured in decibels (dB), lower insertion loss values indicate better performance, as less signal power is lost. Polarization-maintaining (PM) optical switches are crucial components in optical communication and sensing systems, enabling precise and reliable optical signal management. Here, we will explore these metrics to. For the sake of discussion, I have two Cisco switches, Switch1 and Switch2. Use the manufacturer's loss values if available. Dispersion increases with distance and its effects increase with data rate. If you are using a fiber cable with less light loss than expected (for example, in a test environment.