The authors demonstrate a novel reflection-type normally-on two-wavelength modulator by combining two quantum-well structures with different operating wavelengths in a coupled cavity structure. Reflection spectra show simultaneous modulations at wavelengths of 856 and 886 nm in the device consisting of GaAs/AlGaAs and InGaAs/AlGaAs quantum wells for each wavelength. Under separate applied voltages, maximum reflectivity changes of 70 and 54% were obtained for the two wavelengths. To the best of the authors' knowledge, this is the first two-wavelength reflection modulator ever reported.
- Optical modulation
- Semiconductor quantum wells