Demonstration of practical blue waveguide stark-effect modulators of ZnSe/ZnMgSSe asymmetric coupled quantum wells

A practical blue waveguide Stark-effect optical modulator using ZnSe/ZnMgSSe asymmetric coupled quantum wells (ACQWs) has been demonstrated. The device structure is a p-i-n diode with a 50 periods ZnSe(6 ML)/ZnMgSSe(2 ML)/ZnSe(12 ML) ACQW active region grown on an n-GaAs substrate by using molecular beam epitaxy (MBE). The ridge-shape devices are fabricated by wet-etching with a fairly-short effective modulation waveguide length of 13 mu m and are located under a top stripe-electrode. The waveguide modulator exhibits a high modulation depth of 95 % (contrast ratio: 13 dB) under reverse bias condition of 68 V at room temperature at an operating wavelength of 458 nm.