5:00 PM - 5:15 PM
[19p-Z05-13] Performance improvement of BOCDR strain distributed measurement system by combined use of double-frequency modulation scheme and intensity modulation scheme
Keywords:Optical fiber
In this presentation, we proposed a method to improve the performance of Brillouin Optical Correlation-Domain Reflectometry (BOCDR) method, which is a distributed optical fiber sensor proposed by our group.
The BOCDR method has a trade-off between spatial resolution and measurement range, and it is difficult to improve both at the same time. The solution to this problem is double-frequency modulation. This is a method of improving resolution while maintaining the measurement range by performing frequency modulation of the light source at two frequencies that are integral multiples of each other. However, as performance improves, background light noise that causes measurement errors is generated, making measurement difficult. Therefore, we considered using the light intensity modulation method together as a method to reduce the background light noise. By applying intensity modulation to the light source, the intensity of the part where the frequency change is slow is weakened and the background light noise is reduced.
In this presentation, the conditions of the double-frequency modulation method and the light intensity modulation method are investigated by simulation. In addition, we actually measured the distribution and confirmed the effect of both methods.
The BOCDR method has a trade-off between spatial resolution and measurement range, and it is difficult to improve both at the same time. The solution to this problem is double-frequency modulation. This is a method of improving resolution while maintaining the measurement range by performing frequency modulation of the light source at two frequencies that are integral multiples of each other. However, as performance improves, background light noise that causes measurement errors is generated, making measurement difficult. Therefore, we considered using the light intensity modulation method together as a method to reduce the background light noise. By applying intensity modulation to the light source, the intensity of the part where the frequency change is slow is weakened and the background light noise is reduced.
In this presentation, the conditions of the double-frequency modulation method and the light intensity modulation method are investigated by simulation. In addition, we actually measured the distribution and confirmed the effect of both methods.