Optics Letters
Experimental demonstration of bidirectional light transfer in adiabatic waveguide structures
Tong Liu, Alexander S. Solntsev, Andreas Boes, Thach Giang Nguyen, Christian Will, Arnan Mitchell, Dragomir N. Neshev, Andrey A. Sukhorukov
Abstract
We propose and demonstrate a novel type of optical integrated structure consisting of three adiabatically coupled waveguides arranged in an N-shaped geometry. Unlike conventional adiabatic three-waveguide couplers mimicking the stimulated Raman adiabatic passage process which utilize solely the counter-intuitive coupling and, thus, operate only in one direction, our structure achieves complete bidirectional light transfer between two waveguides through the counter-intuitive and intuitive coupling in either direction over a wide wavelength range. Moreover, the light transfer through the intuitive coupling is more efficient and robust than through the counter-intuitive coupling.