Design method of high throughput laser scanning projection system based on broad-area laser diode

Laser scanning projection is regarded as a highly promising projection technology owing to its advantages of a wide color gamut and high energy efficiency. However, its application scenarios are constrained by the insufficient output power of single-mode laser diodes. The adoption of broad-area laser (BAL) diodes offers a potential solution, but their poor beam quality and low modulation frequency hinder the achievement of high resolution and high frame rate projection. This paper analyzes the resolution-determining mechanisms within BAL diode-based scanning projection systems and the parametric trade-offs in MEMS scanners. Based on this, an optimized configuration is proposed to rationally align the emitting area geometry of BAL diodes with the MEMS scanning direction. Meanwhile, multi-laser inputs and scanning are achieved through a newly developed optical engine architecture, ultimately ensuring adequate projection resolution and frame rate under constrained MEMS scanner parameters. A comprehensive design example, accompanied by full performance and tolerance analyses, is presented, which achieves high resolution (720P), high frame rate (60 Hz), low distortion (<3.02%), and ultra-short throw ratio projection (0.29) with watt-level optical power output. The proposed design methodology addresses the existing limitations in output power, modulation frequency, and throw ratio, thereby significantly expanding the application scope of laser MEMS scanning projectors.