What do CP and SP mean in an optical power meter

CP stands for Continuous Power, and SP stands for Sampled or Single Pulse Power in optical power meters.

Meaning of CP and SP

• CP (Continuous Power): This mode measures the average optical power of a continuous light signal. It is used when the light source emits a steady, uninterrupted beam, such as from a continuous-wave (CW) laser or LED. The meter continuously monitors the power and displays a stable reading, which is essential for evaluating transmitter output or link loss in fiber optic systems .
• SP (Sampled or Single Pulse Power): This mode is designed for pulsed light sources, such as Q-switched or mode-locked lasers. Instead of averaging over time, the meter captures the power of individual pulses or a sampled portion of the pulse train. This is important when the pulse repetition rate is high, and the user needs to measure peak or pulse-specific energy rather than the continuous average .

Practical Usage

• CP mode is typically used for standard fiber optic testing, such as measuring the output of a transmitter, checking link loss, or verifying power at a receiver port. It provides a reliable reading for continuous signals in dBm or mW .
• SP mode is used when dealing with pulsed lasers or systems where the optical signal is not continuous. It allows technicians to evaluate pulse energy, peak power, or transient behavior, which cannot be accurately captured in CP mode .

Summary

In essence, CP and SP are measurement modes on an optical power meter that allow the device to handle different types of optical signals: continuous versus pulsed. Selecting the correct mode ensures accurate readings and proper assessment of fiber optic system performance.