Heterostructure field-effect transistor optical modulator in the InGaAs/AlGaAs material system

Abstract

The heterostructure field-effect transistor optical modulator is demonstrated in a waveguide geometry using strained InGaAs quantum wells. A 20 μm×300 μm device is shown to have a contrast ratio of 35:1 using a 2 V swing from −1 to +1 V, which results in a figure of merit of 25.7 dB/V mm for this device. A Kramers–Kronig transformation is used to show the potential low chirp available at maximum contrast ratio for this device. Wavelength compatibility with a 5 μm×400 μm heterostructure field-effect laser from the same wafer is demonstrated, and the corresponding heterostructure field-effect transistor is also demonstrated from the same wafer with a transconductance of 120 mS/mm for a 1 μm gate length.