Method for Polarization-Resolved Measurement of Electroabsorption

Photonic integrated circuits often use semiconductor components such as amplifiers, detectors, and electroabsorption modulators. For a proper circuit design, it is important to know the absorption spectrum of these semiconductor optical components and how it depends on an applied electric field. We propose a fast and accurate method that uses a compact segmented contact structure to measure the absorption characteristics. The method is based on measuring the transmission of amplified spontaneous emission (ASE) from a single forward-biased section through a varying number of reversely biased absorbing sections. Provided the ASE source emits light in both polarizations, the method measures the absorption spectra for both polarization modes simultaneously, without the need for a polarization filter in the measurement setup.