Ultrahigh-resolution optoelectronic vector analysis utilizing photonics-based frequency conversion

Abstract

Optoelectronic devices, such as photodetectors (PDs), integrated coherent receivers (ICRs) and microwave photonics integrated circuits (MPICs), are the fundamental and essential components to bridge the optical world and the electronic world and massively applied in emerging fields. Optoelectronic frequency responses, representing the optical-to-electrical conversion efficiency at different frequencies, are the primary and critical parameters for optoelectronic devices, which are essential and of great importance to be precisely measured in their development, manufacture and application. To achieve ultrahigh-resolution and multi-dimensional characterization, optoelectronic vector analyzers (OEVAs) utilizing photonics-based frequency conversion have been proposed and demonstrated. Benefitting from photonics-based frequency conversion and ultrahigh-resolution microwave technologies, the ultrahigh-resolution and broadband optoelectronic frequency responses are de-coupled from the joint frequency responses. Theoretically, sub-Hz frequency resolution together with hundred-GHz measurement range is potentially achievable. However, limited by the high-order sidebands and the high-order intermodulation sidebands stimulated by the nonlinear electro-optic conversion, the measurement accuracy is deteriorated and the dynamic range is considerably limited. Additionally, for the on-chip measurement, the relatively narrow working bandwidth of the on-chip electro-optic modulators places a restriction on the measurement range. Recently, great efforts have been devoted to eliminate the nonlinear errors, improve the dynamic range and extend the measurement range. In this paper, the influence of the high-order sidebands and high-order intermodulation sidebands on the measurement accuracy and the dynamic range of the proposed OEVA are comprehensively investigated. The techniques for implementing high-accurate and broadband OEVAs are reviewed and discussed.