Self-starting generation of tri-band frequencies using a dual-parallel Mach–Zehnder modulator-based optoelectronic oscillator

A scheme for multi-band frequency generation is proposed and experimentally demonstrated using a dual-parallel Mach–Zehnder modulator (DPMZM)-based optoelectronic oscillator (OEO). The principle of this generator is theoretically described in detail. It is found that multiple frequencies with a small power variation can be produced by setting the three working points and the modulation depth of the DPMZM. In the proving experiment, an 8-GHz fundamental oscillation with a side mode suppression ratio of 44 dB is generated. The phase noise is measured to be −96.8 dBc/Hz @ 10 KHz offset with a 100-m and 1-Km optical fibre used in the two oscillation loops. When the oscillating signal is applied to drive the two sub-modulators in the DPMZM, doubled and tripled frequencies are produced at the same time, and the phase noises of the two frequencies are also measured to be −90.2 dBc/Hz and −85.9 dBc/Hz @10 KHz, respectively.