High speed and low loss, bulk electroabsorption waveguide modulators at 1.3 mu m

Bulk InGaAsP electroabsorption waveguide modulators based on a novel multiquaternary layer design which have a tapered-fiber-modulator-tapered-fiber insertion loss as low as 4.5 dB and a small-signal frequency response in excess of 11 GHz at lambda =1.33 mu m are described. This design allows one to decouple somewhat the electrical and optical properties of the device. By choosing the appropriate quaternary composition of the core and the cladding layers, the coupling to a tapered fiber can be optimized, while the position and thickness of the p-i-n junction can be varied independently to meet operating voltage and speed requirements without affecting the waveguide mode. A -3 dB small-signal modulation bandwidth in excess of 11 GHz was measured.<
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