for Optical Communications Final test Contents include: normal temperature test, high and low temperature test, transmission test, burst test, ground isolation test.

 Module test Equipment: BER tester, spectrometer, oscilloscope, DC regulated power supply, spectrometer, single-mode adjustable attenuator.

1. Transmit Eye Diagram:

Definition: Input the output light to the vertical amplifier of the oscilloscope, and synchronize the sawtooth wave cycle that generates horizontal scanning with the symbol timing, then an image similar to the human eye can be observed on the oscilloscope screen, which is called an eye diagram.

2. Extinction ratio: Er

Definition: Under full modulation conditions, the logarithm of the ratio of the output optical power when the logic “1” is high to the output optical power when the logic “0” is low.

3. Side Mode Suppression Ratio: SMSR

Definition: Under the worst reflection conditions and full modulation conditions, the ratio of the maximum power (or amplitude) of the main longitudinal mode emitted by the SLM laser to the optical power (or amplitude) of the adjacent maximum longitudinal mode.

4. Spectral width: Dl

Definition: Root mean square spectral width refers to the root mean square width of the spectral distribution of light-emitting devices measured under standard operating conditions. -20dB spectral width refers to the wavelength interval corresponding to both sides of the spectral line when the peak wavelength emitted by the laser drops by 20dB at the maximum under standard working conditions.

5. Receiving sensitivity: Pr

Definition: Under a certain bit error rate condition, the minimum input average optical power that the receiving component can receive.  

6. Module reliability test

  PS laser section   After recording, the module has related functions. The modules roughly craft these pieces. Lasers do not have a large share in it, but the cost is indeed the most expensive.