A Regulated Pulse Current Driving Technique in Green Laser Synthesis With Electrical to Optical Conversion Efficiency Improvement for Mobile Projectors

In this paper, we propose a regulated pulse current laser driver with the frequency double approach to synthesize green laser. Experiment results show that green laser synthesis conducted with the regulated pulse current driving (RPCD) technique has an electrical to optical conversion efficiency improvement of up to 78%, as compared to the DC driving technique with mean driving current of 250 mA at room temperature. This driver was fabricated with a 0.5 μm CMOS process and has a modulation frequency range of 300 kHz-700 kHz, a wide range of peak pulse current between 120 mA-900 mA with the average current range between 0 mA-280 mA. This paper not only demonstrated the synthesize procedure of green laser but also proposed driver with the RPCD technique enhances the electrical to optical conversion efficiency of green laser and its implementation in integrated circuit, making it a good match with green laser microchip to create a low cost, compact-sized device ideal for mobile projector applications.