Using a $\hbox{Si}_{3}\hbox{N}_{4}$ Ring Resonator Notch Filter for Optical Carrier Reduction and Modulation Depth Enhancement in Radio-Over-Fiber Links

Optical carrier reduction via the use of a Si 3 N 4 ring resonator notch filter (RRNF) is proposed and experimentally demonstrated as a means for improving the modulation efficiency in 10-GHz radio-over-fiber (RoF) links. The realized filter is characterized in both the optical and microwave domains and is then exploited in an RoF test bed. Experimental results show a modulation depth improvement of up to 9 dB.