A laser pointer for realizing integration of red and green light

At present, laser pointers are widely used in teaching demonstrations, meeting instructions, etc. The earliest laser pointer used was a red laser pointer. The principle is to use a red light module (LD + plastic lens) as a light-emitting element. The red light LD can directly convert the current into a red laser output, which has a high conversion efficiency. , So the battery life is longer. However, the human eye is not sensitive to red light. In the case of bright lights or outdoors, the red light indicator is difficult to attract the attention of the participants due to the insufficient brightness. In recent years, green laser pointers have emerged with all-solid-state laser technology and microchip laser technology. Its structure is composed of 808nmLD, laser crystal and frequency double crystal. The green laser in the laser pointer is usually in the form of a microchip laser, the cavity shape is a flat cavity, the pumping method is LD end pumping, and the frequency doubling method is intracavity frequency doubling. First, the current passes through the LD to generate 808nm near-infrared light, then passes through the laser crystal to generate 1064nm laser, and then passes through the frequency double crystal to generate 532nm green laser. Due to the need to undergo multiple conversions, the cavity type is unstable, and the conversion efficiency is not high. Generally, the conversion efficiency of the green laser pointer is less than 20% or even lower, and the pump power required is very high, so its power consumption is serious. Tens to hundreds of times that of ordinary red laser pointers, so the battery life of laser pointers is short, which is not conducive to long-term use.