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.