Extinction ratio compensation by free carrier injection for a MOS-capacitor microring optical modulator subjected to temperature drifting

We have analyzed the temperature stability of a MOS-capacitor microring optical modulator that was designed for critical coupling. We found that free carrier injection through DC bias control can compensate the extinction ratio (ER) drop that was caused by temperature drifting. 0.22degC temperature drifting would drop the ER to 5 dB without DC bias and 8.7 V DC bias could extend the 5 dB limit to 1.86degC temperature drifting.