Method and system for alignment and/or stabilization of an entangled photon source

Abstract

It is claimed a method for alignment and/or stabilization of an entangled photon source (2) with the steps, i) generation of a polarized pump beam (10) by a pump laser (1); ii) generation of entangled photons (20) by guidance of the pump beam (10) to a non-linear element (21) in the source (2) via one or more alignment means. According to the invention the method comprises the steps iii) measurement of the pump beam (10) after the generation of the entangled photons (20) by spatial mode filtering of the pump beam (10) and detection of the spatial mode filtered pump beam (11) after the generation of the entangled photons (20); iv) generation of a control signal (12) based on the spatial mode filtered pump beam (11) in a control means (5); v) adjustment of the one or more alignment means by the control signal (12) in order to align and/or stabilize the spatial mode of the pump beam (10) in the source (2).

Dependencies are inferred from the claim text.