High-Power Chaotic Green Laser Beam Generated by Perturbing a 520 nm Laser Diode with Optical Feedback

We designed a compact and efficient high-power laser that generates chaotic green light by perturbing a 520 nm laser diode with optical feedback. This achieved a continuous output power of 30 mW with a bandwidth of more than 1 GHz and an electrical-to-green conversion efficiency of 6.25%. All possible chaotic states were demonstrated for different diode-driving currents and feedback intensities. The FWHM and the peak side-lobe level (PSL) are affected by the injection current and feedback intensity. The FWHM increases with increasing feedback intensity, and the PSL increases with both injection current and feedback intensity. The compact chaotic laser could be used in underwater detection to suppress backscattering because of its intrinsic intensity modulation at high frequency. We finally found the optimum range of chaotic states for underwater detection, for which the ratio of input current to threshold current is 1.5 : 2.1.