After the installation and the adjustment of the input mirror finished,we tried to align the beam in order to receive green light at the end bench. We tried for pretty long time but even we looked directly at the second target with eyes, we can only see the reflection from the tube on the edge of the target which is more reflective than the central part.
So we decided to increase laser current to have higher power in infrared and also in green, the current we used before is 1.040A which gave a 8mW-green power at the end of the bench, now we increased the current to 1.2A which gives out a three times green power around 27mW at the end of the bench.
With this power we easily found the beam at the second target and also received it at the end bench.By looking through the window of the end chamber, we better adjust the beam on the end mirror and let it pass more or less the center of it, luckily we got the flash of the cavity with the first try.
The other thing we did before closing the chamber is that we sent the beam out of the chamber to the corridor again after the BS, tried to superpose the green and infrared both in the near field and the far field with the last two infrared steering mirror on the bench. Although considering the air fluctuation in the corridor, two beams moved a lot, but we did our best to make them overlap at 300m.