What Is an Optical Power Meter?

An optical power meter is a device used to measure power from optical signals in cables or fibers. An optical power meter works with fiber optics and cannot accurately read energy from other cable types. An optical screen on the meter allows the user to see the power coming from the optical cables and the power’s wavelength. Accuracy can be a problem for novice users, because the power meter must be set to the correct wavelength or the power levels will be wrong. Aside from reading how much power is coming from an optical fiber source, these meters also are used for continuity testing.

The only type of cable that can be checked with an optical power meter is a fiber optic cable, but this is not the only type of power meter that can be used to check such a cable. There also are light meters, lux meters and photometers, but optical power meters function differently from these other devices. This unit reads the average power output and usually does not capture power that deviates from the average. These units are best for users that just want a snapshot of the power reading and not a record of the power levels over an extended amount of time.

There is another optical aspect to an optical power meter — an optical screen that displays results of the test. The most common reading is the amount of energy being created by the fiber optic cable. Some devices also show the wavelength of the fiber optic cable, which can be useful for calibrating the device.

To get an accurate energy measurement, the optical power meter must be set to the correct wavelength. This process is usually easy for experienced users, and most users will already be aware of the wavelength. If the wavelength is set incorrectly, then it will not display the right power reading, which can be bad, because some applications will need an exact measurement. This meter is able to test a broad light spectrum and, it if it incorrectly calibrated, it will result in a high or low reading.

Aside from reading energy levels, an optical power meter also is commonly used for continuity testing between many different fiber optic cables. Operators will test the entire length of the cable to ensure the power is continuous and that there are no spikes or drops anywhere in the fiber optic wire. These power meters need a special function known as test tone detection for the best results with continuity testing.