A brief comparison of optical pathlength difference and various definitions for the interferometric phase

10th International LISA Symposium

Wanner, Gudrun^1,2 ; Schuster, Sönke^1,2 ; Tröbs, Michael^1,2 ; Heinzel, Gerhard^1,2

Max-Planck-Institute for Gravitational Physics (Albert-Einstein-Institute), Callinstr. 38, Hannover

D-30167, Germany^1

Leibniz University of Hannover, Hannover, Germany^2

关键词: Cross-couplings;    Interferometric phase;    Low noise lasers;    Optical pathlength differences;    Precise definition;    Single element;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/610/1/012043/pdf
DOI  :  10.1088/1742-6596/610/1/012043

来源: IOP

【 摘 要 】

In this paper we discuss that the phase readout in low noise laser interferometers can significantly deviate from the underlying optical pathlength difference (OPD). The cross coupling of beam tilt to the interferometric phase readout is compared to the OPD. For such a system it is shown that the amount of tilt to phase readout coupling depends strongly on the involved beams and their parameters, as well as on the detector properties and the precise definition of the phase. The unique single element photodiode phase is therefore compared to three common phase definitions for quadrant diodes. It is shown that neither phase definition globally shows the least amount of cross coupling of angular jitter.