Wavelength tuning in a grating-assisted vertical coupler filter using quantum well electrorefraction

Abstract
We present a demonstration of the electro-optic tuning in a GaAs/AlGaAs quantum well vertical codirectional coupler filter. Tunable range over 2 nm was realized through the quantum-confined Stark effect with a tuning rate of 0.28 nm/V2 for transverse magnetic polarization. A filter bandwidth as narrow as 1.7 nm (full width at half-maximum) at 830 nm with a coupling region length of 490 μm was obtained.