Characterization of integrated photonic devices with minimum phase technique.

Spurious reflections can preclude the accurate experimental characterization of integrated optical devices. This is particularly important for facet reflections in high refractive index platforms such as Indium Phosphide (InP) or Silicon-on-Insulator (SOI) when no anti-reflective (AR) coating is used. In this paper we present a novel method to recover the original device characteristics from the measured power transmission in the presence of such reflections. Our approach uses minimum phase techniques to reconstruct time domain information which is filtered to remove the reflection artifacts. A criterion to assess if a certain device exhibits the minimum phase characteristics required to apply the technique is given. Simulated and experimental results for multi-mode interference couplers (MMICs) in SOI without AR coating validate the technique.