Vertical 1.3 μm optical modulator in silicon-on-insulator

Reported is a new optical intensity modulator at 1.3 μm which utilizes a Fabry-Perot resonant cavity implemented by silicon-on-insulator technology to achieve a high modulation depth. A p-i-n diode modulator is placed outside the cavity. The 1.3 μm light comes in from the top, bounces back-and-forth inside the Fabry-Perot cavity, and is partially reflected back and partially transmitted through. At resonance, the reflectance is minimized. Forward biasing the p-i-n diode modulates the phase of the laser light inside the cavity and shifts the resonance of the cavity to convert the phase modulation to intensity modulation. Device fabrication and testing are outlined