Reports 1-1 of 1 Clear search Modify search
IOO (Laser Bench)
masayuki.nakano - 17:56 Wednesday 07 June 2017 (2871) Print this report
double path AOM installed

[Nagano, Kokeyama, Nakano]

The double path AOM was installed. So far the AOM was installed but not turned power on and the laser just passed through the AOM to simplify the system. And the measurement has been done, so we started installing the double path AOM.

The concave mirror on the one axis stage was installed after AOM, and reflected the 1st diffraction light. Before starting AOM installation, irises are put for alignment references, and TEM00 resonance was easily found with those references. Then with transmission light of TEM00, the concave mirror was aligned finely. The transmitted power was about 200mV on PDA100 which is 25% comparing to before the installation.

The reference cavity was locked with double path AOM configuration.

The concave mirror position is not fine optimized, so tomorrow we would optimize that with using QPD.[Nagano, Kokeyama, Nakano]

The double path AOM was installed. So far the AOM was installed but not turned power on and the laser just passed through the AOM to simpify the system. And the measurement has been done, so we started installing the double path AOM.

The concave mirror on the one axis stage was installed after AOM, and reflected the 1st diffraction light. Before starting AOM installation, ailises are put for alignment references, and TEM00 resonance was easily found with those references. Then with transmission light of TEM00, the concave mirror was aligned finly. The transmitted power was about 200mV on PDA100 which is 25% comparing to before the installation.

The reference cavity was locked with double path AOM configration.

The concave mirror posission is not fine optimized, so tomorrow we would optimize that with using QPD.

Comments to this report:
masayuki.nakano - 19:00 Friday 09 June 2017 (2880) Print this report

[Nagano, Yamamoto, Nakano]

The concave mirror was fine aligned so that the input beam to the reference cavity does not jit. The DC QPD was put about 2m after from AOM.
The procedure of alignment was as below

1. make reference.
To make sure that the laser reflect nomaly on concave mirror, the power after the double path AOM was measured and align the concave mirror to make power maximum.  Align the cavity with transmitted power. Then zeros the QPD output with steering mirror before QPD. We used the QPD and cavity as an alignment reference.

2.optimize the position
Inject the signal (2Vpp, 5Hz, 7.5V offset) and excited the beam jitter. With measuring the spectrum of yaw motion with diaggui, optimized the position of the concave mirror with a micrometer attached stage. The spectrum after optimization was attached. The beam jitter at 5 Hz was dumped and 10Hz was excited, that means the alignment is at around the best position.

Non-image files attached to this comment
Search Help
×

Warning

×