We perform a rigorous characterisation of multiport waveguide circuits. These devices were fabricated using an ultrafast laser inscription process which permits uniquely three-dimensional circuit fabrication not possible using standard lithographic means. To infer device manipulation of an arbitrary input state of light (i.e. intensity and phase transformations), we perform device interrogation with coherent input states. We demonstrate that the inscription process, and output from coherent state interrogation combined with a maximum likelihood estimation algorithm, provide a rapid prototyping system for waveguide circuits acting on quantum states of light. This opens the way for more advanced multiport structures exploiting additional paths, input states and arbitrary phase relationships.

Date Published: 4 March 2015
PDF: 6 pages
Proc. SPIE 9377, Advances in Photonics of Quantum Computing, Memory, and Communication VIII, 93770Y (4 March 2015); doi: 10.1117/12.2081030

Published in SPIE Proceedings Vol. 9377:
Advances in Photonics of Quantum Computing, Memory, and Communication VIII
Zameer Ul Hasan; Philip R. Hemmer; Hwang Lee; Alan L. Migdall, Editor(s)