The spectrum analyzer is a commonly used test instrument in fiber-optic communication products. This paper takes the AQ6370 spectrum analyzer as an example to combine the usual test work, and introduces some methods for measuring the conventional parameters using the spectrum analyzer.
I. Overview
The spectrum analyzer is a commonly used instrument in the usual optical communication wavelength division multiplexing products. When the WDM system first appears, it is often used to test the signal wavelength and optical signal to noise ratio. Its main feature is that the dynamic range is large, generally up to 70dB; the sensitivity is good, up to -90dBm; the resolution bandwidth is small, generally less than 0.1nm; it is more suitable for testing optical signal-to-noise ratio. In addition, the measurement wavelength range is large, generally 600~1700nm. However, the test wavelength accuracy is not as accurate as the multi-wavelength meter.
Yokogawa AQ6376 Spectrometer
Anritsu MS9740A spectrometer
A spectrum analyzer can be used for the measurement of the spectrum, the signal power of each reference point path, the optical signal to noise ratio of each reference point, the gain coefficient of each wavelength of the optical amplifier, and the gain flatness. The spectrum analyzer now also integrates WDM analysis software, which can conveniently display the parameters such as the center frequency, power, optical signal-to-noise ratio of each wavelength of WDM in a menu.
Second, the test of commonly used parameters
The screen of the spectrum analyzer displays measurement conditions, marker values, other data, and measurement waveforms. The names of the various parts of the screen are shown below:
Figure 1: The names of the various parts of the screen
2.1 Measurement of spectral spectral width
The spectral width is the bandwidth of the spectrum. The spectral width of the LD and LED can be measured using a spectrum analyzer. When measuring the spectral width of the spectrum, pay special attention to the resolution of the spectrum analyzer system. In principle, the resolution of the spectrum analyzer should be less than 1/10 of the spectrum width of the measured signal. Generally, the recommended setting is at least less than the measured value. 1/5 of the signal spectrum width.
In actual measurement, in order to accurately measure data, the resolution bandwidth is generally selected to be 0.1 nm or less. The resolution bandwidth RES is located in the first item in the SETUP menu, and the size of the resolution bandwidth to be set can be directly input. As shown in Figures 2, 3, and 4 below (the difference between the spectral shapes is only shown in the figure), when the selected resolution bandwidth is different, the spectral shape observed from the spectrum analyzer is very different, and the measured The difference in spectral width.
Figure 2: Spectral shape at resolution bandwidth RES = 0.5 nm
Figure 3: Spectral shape at resolution bandwidth RES = 0.1 nm
Figure 4: Spectral shape at resolution bandwidth RES = 0.02 nm
While observing the spectral spectrum width, parameters such as the center frequency, bandwidth, peak power, and side mode suppression ratio of the spectrum can also be read by the spectrum analyzer. At the same time, the MARKER menu can be started and the corresponding identification can be performed to conveniently measure the parameter values ​​to be tested.
Original compatible with usable medical device battery, authorized by authentic manufacturer
On time delivery, factory inspection, 5 years warranty
Defibrillator Battery
Shenzhen Sunwind Energy Tech Co.,Ltd , https://www.sunwindbatterylm.com