Calibration factor of Optical BPF

[vinoptic]

Hello all

I have been working on a Raman OTDR setup over the past few months as part of my project work. I have been using an optical BPF which takes backscatter from the fiber under test as input and gives the stokes' and anti-stokes' spectrum as outputs. My guide asked me to calculate the "calibration factor" for the BPF so as to accurately draw up the temperature map of the fiber,which is the ratio of the AS/S spectrum.

To calculate the cal. factor, I passed light from a broadband source (LED) to the input of the BPF and measured the spectrum at the Stokes' and Anti-stokes' spectrum at the output. I would like to know if

1) Is this is the right method to get to the cal factor?
2) How to get to the calibration factor from the data in hand?

thanks
vin

 

[eljose79]

ay

Hello Vinay,

Thank you for sharing your project work with us. It sounds like you are making progress with your Raman OTDR setup. To answer your questions:

1) Yes, using a broadband source and measuring the stokes' and anti-stokes' spectrum at the output is a common method for calculating the calibration factor for a BPF. However, it is important to ensure that your broadband source is stable and has a known spectral profile to ensure accurate measurements.

2) To calculate the calibration factor, you will need to use the ratio of the anti-stokes' and stokes' spectra. This ratio is dependent on the temperature of the fiber under test. By comparing this ratio to the known temperature of the fiber, you can determine the calibration factor. You may also need to consider other factors such as the power levels of the input and output signals, as well as any losses in the BPF itself.

I hope this helps. Good luck with your project! Let us know if you have any further questions.