Phase-locking the two lasers:
Updates:
- Although when we talked about adjusting the MZ-phase, we decided that having the phase/path length control with fiber components might be better initially (Refer Attachment 2), for now I began doing everything in free-space.
- Attachment 1 shows the setup as it is now. Previously I'd placed polarizing beam splitters instead of 90/10 beam-splitters because I thought it would be easier to work with, but now changed my mind and decided to stick with what we planned.
Next steps:
(Once the beat is obtained on the spectrum analyzer)
1. Adjust set-point temperatures to adjust beat frequency to the right frequency.
Since ideally we want the two frequencies to be identical, it might be a good idea to add an AOM to one of the paths so that the first order beam is mixed with the other laser and this beat be compared to a stable reference for phase-locking.
But, initially we plan to skip the AOM.
2. Adjust the PID parameters if needed
3. Add electronic components
- Measure the laser frequency noise
29 Oct 20:
I've added Attachment 3 -- which is the current free space version and some PLL electronics.
- It does not show the Mach-Zehnder part as that will be added only later
- This setup is asymmetric but in a future version we will change that |