The only way to generate a green laser beam is to start

why? Because there is actually no green laser pointer. The only way to generate a green laser beam is to start with a high-power (100 to 300 mW) infrared laser diode, and then go through a complicated process to convert the invisible IR beam into visible green. Please pay attention to these numbers-starting from 100 to 300 mW of power, only a 5 mW beam is produced. The rest of the energy is not emitted in the form of light, so the laws of thermodynamics say that it must appear in the form of heat. It is not a friend of diodes. If the diode overheats, it is expected to shut down.

The key detail of VCSEL construction is that the thickness of each layer in the mirror stack must be equal to a quarter of the laser wavelength. This step (and the π phase change that occurs when light reflects from the interface of a material with a higher refractive index) ensures that all light returning to the cavity has the same phase, regardless of which part of the mirror provides reflection. . Produce constructive interference to support VCSEL emission. In this regard, pairing gallium arsenide with AlGaAs or AlAs is a good choice because the refractive index of the material varies greatly. This means that substantial reflection occurs at the interface inside the mirror, and each mirror has about 20 pairs of layers that can reflect 99% of the light.
Just like electronic watches 15 years ago, due to the new development of laser technology, laser engraving machine pointer teams have recently become very cheap. They are widely available in electronic stores, novelty stores, mail order catalogs, and many other sources. In the price range of other electronic toys, their prices are low. A woman wrote to the Laser Society of America, describing how other mothers she knew bought laser pointers for their elementary-age children, and they could imitate them. Luke Skywalker and Darth Vader fought with them.


Nichia’s design has created a new situation and completely abandoned the nitride objective lens. However, whether this makes VCSEL manufacturing easier remains to be seen. After the cavity grows, it must be removed from the substrate that lays the foundation for its growth. Then, Nichia still insists on the design. In 2009, engineers announced that the output of the blue laser pointer would be changed from sapphire to GaN. 0.14 mW increased to 0.62. mW. This change has improved material quality and reduced defects by three orders of magnitude.