In fiber-optic networks, optical fiber detection plays an important role both in the installation of new fiber and overhaul of older optical fibers. It is well known that optical power meters are used to measure optical power and detect the light loss. This article will focus on the use of optical power meter and purchase.
In simple terms, the optical power is the "brightness" or "intensity" of the light. In the fiber network, the unit of the optical power is usually expressed in milliwatts (mw) and decibels (dBm), where the relationship is: 1mw = 0dbm, that is, 2mw = 3dbm, it should be noted that less than 1mw decibel milli is negative.
Open the network optical device, just use an optical power meter and an optical fiber connector adapter can measure the transmitter or receiver power.
Before measuring 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 side, the receiver's power can be measured, or it can be connected To the light source, measure the power of the transmitter; Finally, write down the measured value, compare it with the power value specified by the device to see if it is within the specified floating range.
In addition to measuring the optical power, the optical power meter can also be used with the light source to measure the optical loss.
Optical fiber loss is the light from the transmitter to the fiber when the power and light to the receiver when the power difference, to measure fiber loss, not only the need for the optical power meter, also need light. In general, the measurement of multi-mode fiber loss, the need to use 850 / 1300nm LED light source, and measurement of single-mode fiber loss, the need to use 1310 / 1550nm laser light source. In addition, in order to accurately measure fiber loss, it is necessary to make the test environment and conditions of the fiber and connector similar to the actual working conditions, that is, select the appropriate light source and fiber optic cable, and the cable has a standard transmit power, the power of the light source without any influences.
At present, there are two main ways to measure fiber loss: one end loss measurement method and two end loss measurement method. Single-ended loss measurement method only uses the transmission cable, and the double-end loss measurement method in addition to using the transmission cable, the power meter is connected to a receiving cable. The single-ended loss measurement measures the losses generated by the connection of the connector to the transmit cable and the losses generated in the fiber, connector, or other connectors. As a result, each connector can be tested separately, the best way to measure fiber jumpers; the double-ended loss measurement measures the losses between the two connectors and all the fibers, including the loss between the connector and the connector. The following figure shows the specific information of the two measurement methods, in which the left side of the single-ended loss measurement method, the right side of the double-ended loss measurement method.
An optical power meter is a useful tool for optical fiber measurement applications such as optical power measurement and fiber loss measurement. Due to the specific application of the user, it is necessary to select the appropriate optical power meter:
1. Select the optimal probe type and interface type
2. Evaluate calibration accuracy and manufacturing calibration procedures to match your fiber and connector requirements
3. Make sure that the model of the optical power meter is the same as the desired measurement range and display resolution
4. Have the function of measuring the direct insertion loss (dB)