Light coupling and performance of LC modulated photonic integrated circuits

Abstract

Coupling light into a photonic integrated circuit (PIC) is usually the most challenging task to characterize these circuits. PIC connections between components are made of light waveguides whose section is often of the same order as light wavelength, i.e., 1-5 ?m or even less. Waveguides may become active by inserting additional layers of electrooptic materials [1], either as a component within the light path, or deposited onto the waveguide affecting the evanescent field of the guided light. Testing the light behavior inside the PIC and comparing the experimental results with those predicted in modeled circuits may be hampered by the tiny cross-section of the waveguides ?especially monomode guides? and the arduous light coupling from external sources.