[Fujii, Miyo, Nakano, Enomoto]
(Work on Aug.13)
We tried to verifiy the calibration of the LS oplev for each test mass.
= How we did =
- lock the green laser to the arm with its frequency as an actuator.
- excite the TM in L at 1.82 Hz
- measure the transfer function from the feedback signal to the green frequency to output of the LS oplev.
- calibrate the feedback signal in V into arm length change by the following equations:
δL(green) [um] = λ/2 / FSR * AAOM * V = (1.064/2)[um] / 50[kHz] * (+/-)0.42 [MHz/V] * V [V]
= Results =
IX: δL(OL)/δL(green) = 1.23
EX: δL(OL)/δL(green) = 2.34
IY: δL(OL)/δL(green) = -1.06
EY: δL(OL)/δL(green) = -1.12
= Note =
- These numbers are not yet implemented in the calibration factors in medm
- AAOM is positive for Y arm but negative for X arm