Red Lasers :
The red laser is the most common of all lasers, the typical operation of most red lasers is between 635 ~ 670nm and have been around for almost 40 years. From xenon ruby to gas lasers to solid state configurations, the red laser has become the most popular color in the laser industry for its longevity since creation back in the 1960's. Today, red laser pointers are dime a dozen and have been manufactured in a variety of configurations. Some examples of red lasers are in the form of key chain lasers, laser pointer pens, portable handheld lasers, laser scanners, oem red laser diodes, pistol and gun sights, household level systems, etc..
5mW 650nm red laser modules are the most common, followed by 670nm. Because of how the human eye perceives frequencies and wavelengths, out of all the red lasers available, 635nm is relatively brighter of the red lasers. Some manufacturers of red dot scope systems provide 630nm wavelengths and are generally brighter than most of the red wavelength. However, these lasers are operating within the orange spectrum and are not the deep rich red color we see with 650nm laser modules. It takes approximately 100mW of 650nm to exponentially see and compare to that of a 5mW 532nm green laser.
This makes 650nm red lasers a useful tool for star gazing and pointing at celestial objects, which was virtually unheard of 5 years ago. 150 ~ 200mW 650nm laser pointers are a good choice for this field. While the greenies have infiltrated astronomy enthusiasts, with most star gazers using 532nm greenies, 650nm star pointers have become un-common, now that 650nm are operating at well over 150mW, these red lasers are making a comeback to the field of astral-pointing.