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How to test the optical power of optical modules?

Date: 2019-11-21 10:12:40 From: C-light Onclick:
After an optical module is made into a finished product, it can be shipped after several steps of testing to ensure the quality of the product. In testing, there are several parameters that are very important. Only when these parameters meet the relevant standards can the optical module perform best. These parameters include: Transmitting optical power, receiving sensitivity, bias current, saturated optical power, extinction ratio and working temperature.
 
Today we will focus on the power of transmitting light. You may probably know its definition, but do you know how to test the optical power of optical modules? Well, Please follow the footsteps of C-light, we will answer for you!
First of all, we need understand: What is the transmitted optical power?
 
The transmitted light power refers to the output optical power of the transmitter terminal of the optical module. In order to DBm As an important parameter of optical module, it will directly affect the quality of network communication.
 
Causes of poor power of optical modules. What are they?
 
* Power resistor mismatch
 
* Bad or bad performance of drive chip.
 
* Launch module TOSA Bad or one of them PD+ Foot weld
 
* LD , LD- Magnetic bead on signal line is bad, missing or wrong.
 
* Storage chip pins (Capacitors, resistors, inductors or magnetic beads ) Bad, missing or wrong.
 
How to test the transmitting power of the optical module?
 
The general tools we use are optical power meter and optical fiber attenuator. The testing procedures are as follows:
 
* Measuring output power of fiber optic transmitter with power meter. The industry standard defines the optical input power of the transmitter and receiver of a specific network standard. The receiver and transmitter should match, and the output power of the transmitter should be within the prescribed range.
 
* The transmitter is connected to the receiver to test whether the transmitter can work normally under the maximum optical input power provided by the transmitter, and then the smallest optical input power receiver can be received by the receiver to see if the receiver can still provide the best performance.
 
* Calculate the attenuation level required for testing. Calculation method: if the transmitter's output power is -15dBm; the minimum optical power of the receiver is -32dBm; the difference between the two is 17dB, then you can use the 17dB optical fiber attenuator and retest the receiver.