Aritomi, Yuhang

Today when I wanted to lock PLL of p-pol, I found p-pol and master laser beat note frequency is close to zero. Then I move this beat note frequency to 150MHz by changing p-pol laser temperature as usual. But I found that I cannot lock PLL by using the current set-up. I didn't realize at that time, actually, I have already put p-pol locking frequency to another side of 0MHz. Then I changed the PLL locking sign and in the end, although everything else was fine, I couldn't find the coherent control error signal.

So please notice next time that if you couldn't lock p-pol PLL by using the current set up, please change p-pol beat note to another side of 0MHz. (different side refers to p-pol laser frequency is higher or lower than master laser frequency)