Fringe-counting technique used to lock a suspended interferometer.
We implement a digital fringe-counting technique to measure in real time the relative mirror displacement of a suspended Michelson interferometer with modulated optical path length for oscillations much larger than the laser wavelength (λ). This provides the proper error signal for a servo mechanism that reduces the relative displacement within λ/2. The implemented technique does not require extra optics or polarizers and thus can be used for interferometric gravitational wave detectors as a starting procedure to get the system locked.
Barone
F
F
Calloni
E
E
Rosa
R D
RD
Fiore
L D
LD
Fusco
F
F
Milano
L
L
Russo
G
G