1.55-μm asymmetric Fabry-Perot modulator (AFPM) for high-speed applications

We explored the possibility of using an aysmmetric Fabry–Perot modulator (AFPM) for the application of high-speed external optical modulation at 1.55 μm. Using ten pairs of AlGaInAs–AlInAs as the bottom distributed Bragg mirror (DBR) and semiconductor–air interface as the top mirror, we demonstrated an AFPM with a 3-dB frequency response around 20 GHz and a dc extinction ratio of 4 dB at a reverse bias voltage of 0–5 V (and sharp extinction ratio drop from 0 to 2 V) at operating wavelength 1.55 μm. With a multiple quantum-well intrinsic region of 900 nm, which consists of 50 pairs of InGaAs–InAlAs (8–10 nm), the modulator has the potential for high-frequency applications.