Abstract

The worldwide installation of broadband optical communication networks calls for high-performance opto-electronic integrated circuits (OEICs). In particular, balanced coherent heterodyne receiver OEICs are currently of great interest due to increased device functionality.^1,2 The main advantage of such receivers compared to single-detector circuits is their near quantum noise limited performance in the presence of weak signals and intensity noise from the local oscillator.¹ In this paper the successful fabrication of a monolithicaliy integrated receiver in the InGaAsP/InP material system, incorporating two semi-insulating ribwaveguides, balanced twin-photodiodes, a junction field effect transistor (JFET), and a resistor, is reported for the first time (Fig. 1). Such components may serve as important building blocks in the OEICs described above. The major advantages of our structure are as follows: 1) Ease of epitaxy: Possibility to grow all layers in one epitaxy on planar substrates. 2) Ease of electrical isolation between the two photodiodes as well as the JFET using semi-insulating InGaAsP for the waveguide layer,3 avoiding additional isolation techniques (e.g. etching, implantation, diffusion) or two-side wafer processing (as proposed in /4/).

© 1991 Optical Society of America