Assuming we have a laser which has some noises (amplitude fluctuation or phase jitter and so on), besides we have a very high Q value Fabry-Perot resonator, if we put the noisy laser output into this FP resonator, what's the noise characteristic of the output light? Could the noises be reduced?
Hi Silas,
If you use a high-Q FP resonator to filter the frequency noise of your laser for example, it will be at the expanse of a much higher amplitude noise. And inversely if you try to reduce the amplitude noise of the laser (assuming you can tune the FP) it will increase the frequency noise. So depending on your application this might not be acceptable. However if you can send some feedback to your laser (current modulation, piezo,...), you might be able to actively stabilize the frequency or jitter of your laser with the FP (look at Pound-Drever-Hall technique).
Cheers.
I do not think it would improve the noise reduction. Inversely, the external resonator would introduce more intensity noise since the external disturbance would be added this way. However, the frequency noise may be improved. It depends. If the laser linewidth is much larger than the high-Q F-P, the linewidth will be filtered as a narrower one which would be beneficial to phase noise reduction.