We all know that fiber inspection plays an important role in fiber optic networks, whether installing new fibers or overhauling old ones. An optical power meter is a tool used to measure power and detect loss. Today, I will tell you about the knowledge of optical power meters in detail.
Optical power meter key analysis
The use of the optical power meter is very simple, provided you know the meaning of each button on the optical power meter. Most optical power meters have 4 keys: on/off key, unit display key for measurement value (displayed in dBM or W), reference value key for measurement result, and wavelength selection key.
What is optical power?
In simple terms, optical power is the "brightness" or "intensity" of light. In optical fiber networks, the units of optical power are usually expressed in milliwatts (mw) and decibel milliwatts (dbm). The relationship between the two is: 1mw= 0dbm, that is to say, 2mw=3dbm, 10*lgmw is the dbm value. It should be noted that decibel milliwatts less than 1mw are negative values.
How to measure power with an optical power meter?
Turn on network optics and measure transmitter or receiver power with just an optical power meter and a fiber optic connector adapter.
Before measuring the power, the wavelength and other parameters of the optical power meter must be set within the specified range; after everything is ready, the optical power meter can be connected to the transceiver end to measure the power of the receiver, or it can be connected To the light source end, measure the power of the transmitter; finally, write down the measured value and compare it with the power value specified by the equipment to see if it is within the specified floating range (to determine the fault of the optical equipment).
In addition to measuring optical power, optical power meters can also be used with light sources to measure optical loss.
How to measure fiber loss with an optical power meter and light source?
Fiber loss is the difference between the power when the light is coupled from the transmitting end to the fiber and the power when the light reaches the receiving end. To measure the fiber loss, not only an optical power meter but also a light source is required. Generally speaking, 850/1300nm LED light source is required to measure the fiber loss of multimode fiber, and 1310/1550nm laser light source is required to measure the fiber loss of single mode fiber. In addition, in order to accurately measure the optical fiber loss, it is necessary to make the test environment and conditions of the optical fiber and the connector similar to the actual working conditions, that is, to select the appropriate light source and optical fiber cable, and the optical fiber cable has a standard transmission power, and has no effect on the power of the light source. Influence.
At present, there are two main methods for measuring optical fiber loss: one-end loss measurement method and two-end loss measurement method. The single-ended loss measurement method uses only the transmitting optical cable, while the double-ended loss measurement method uses a receiving optical cable connected to the power meter in addition to the transmitting optical cable. The single-ended loss measurement method can measure the loss caused by the connection of the connector to the launch cable and the loss caused by the fiber, splice or other connector. Therefore, each connector can be tested individually, which is the best way to measure fiber patch cords; the double-ended loss measurement method can measure the loss in both connectors and all fibers, including the loss between the connector and the splice.
Optical power meter application scenarios
Through today's introduction, I believe that everyone has an understanding of how to measure fiber loss with optical power meters and light sources. If you want to know more about ZR optical fiber series products, welcome customers to come to consult.
