An Indium-phosphide-based monolithically integrated photonic chip comprising of an amplified feedback laser (AFL) and a photodetector was designed and fabricated for on-chip photonic and microwave generation. Various waveforms including single tone, multi-tone, and chaotic signal generation were demonstrated by simply adjusting the injection currents applied to the controlling electrodes. The evolution dynamics of the photonic chip was characterized. Photonic microwave with frequency separation tunable from 26.3 GHz to 34 GHz, chaotic signal with standard bandwidth of 12 GHz were obtained. An optoelectronic oscillator (OEO) based on the integrated photonic chip was demonstrated without using any external electrical filter and photodetector. Tunable microwave outputs ranging from 25.5 to 26.4 GHz with single sideband (SSB) phase noise less than −90 dBc/Hz at a 10-kHz offset from the carrier frequency were realized.
A frequency-tunable and low-timing-jitter O-band regenerative mode-locked laser (RMLL) using an optoelectronic oscillation configuration and electric-controlled yttrium iron garnet (YIG) bandpass filter is proposed and demonstrated. In this scheme, an O-band semiconductor optical amplifier (SOA) is used as the gain medium of the RMLL to realize a dispersion-management-free operation during frequency tuning. With a polarization-maintaining fiber loop of 300 m, we produced a robust frequency-tunable RMLL with a pulse width below 16 ps, phase noises below −123 dBc/Hz at a 10-kHz frequency offset from the carrier frequency, and timing jitter less than 12 fs (integrated in 1-kHz to 1-MHz range) in a frequency tuning range between 10 GHz and 22 GHz.