I think it's possible to observe the interference pattern. While the duration is hard to say, since the parameters of the two lasers with fluctuations cannot be in perfect harmony. In our Coherent Doppler Wind Lidar research, the homodyne/heterodyne pattern of atmospheric returns with Local Oscillator is observed continuously. The two optical signal could be generated from two lasers, but they are not strictly independent sources. Anyway, it's better to make an experiment with two independent lasers. And the interference could be implemented by a 3dB fiber couple. Good luck!
Yes, it is possible. I rememer that there is a very famous experiemnt to show how the photons from two lasers interfere. I am sorry that I cannot recall the paper, you can try to search.
Yes, it is possible, but the system has to be well stabilised. Have a look at this paper:
http://scitation.aip.org/content/aapt/journal/ajp/68/3/10.1119/1.19416
There will always be interference. The question is how quickly will it change. One typically has to work hard to get two lasers stabilized well enough that you can easily observe the interference.
I think, it is always possible to have interference of two waves having same polarization for ultra-short period of time even if they are coming from the two ordinary independent sources of light. But the question is whether it will be a sustained (observable for indefinite period) interference or not.
If you use typical lasers like He-Ne, you need something like 10^-8 s resolution to observe the fringes. If you take two lasers and introduce a relative stabilization by means on an electronic circuit than the fringes are visible for hours (however the lasers are not independent).
http://iopscience.iop.org/0143-0807/33/1/007/article
- Badges
- Science topic