Tapered, resonant DBR transmission filters

Wavelength-tunable optical filters, in the form of resonant distributed Bragg reflector laser filters, have been fabricated and evaluated. The devices are specially designed as transmission filters and have a novel structure, using low coupling strength in the grating and an up-tapered active section, in order to improve the crosstalk performance and the saturation properties. Fabricated devices have 6-8-dB dynamic range and would give less than 1-dB crosstalk penalty in four-channel systems at 13-dB chip gain. System experiments with two 2-Gb/s channels are reported.<
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