Why are lasers often only red?

When you think of "laser", what do you think of? Barcode scanners? Or laser projection pen used in presentations?

There is one thing in common between these devices is that they show only red lasers. But while the spectrum of light has "billions of colors", along with the six main colors, does the laser only have red?

Oh no, if you think only red laser, you are completely wrong. So far, humans have been able to produce many different laser colors by adjusting the wavelength of this type of beam.

The difference between the colors of the laser lies in the wavelength.

How many colors are lasers?

It's like asking "How many numbers are there on the number line? ", The answer is infinity . But in fact, until now humans have only applied lasers with primary colors including red, green, blue and yellow.

The difference between the colors of the laser lies in the wavelength , in which the red laser has the longest wavelength (about 630 - 680 nm). Green lasers have shorter wavelengths (532 nm), but are 10 to 50 times brighter than red lasers and can travel up to 4.8 km away and are often used at construction sites.

The wavelength of the blue laser is 445 nm, but if you think the blue laser will be brighter than green, unfortunately the reasoning is incorrect. We see green lasers shining more because human eyes are most sensitive to this color wavelength. Blue lasers only allow light to have a stronger focus, meaning for greater combustion.

There are countless types of lasers of different colors.

It is also thanks to the high concentration of light that blue lasers are used in many devices, devices that capture, store and print image information such as laser printers, CDs, CD players, and DVDs. .

Yellow laser has a wavelength of 593.5 nm and is widely used in medicine.

So why do we often see only red lasers?

It's simple, because it's the easiest laser to make.

To get a red laser, one only needs a standard semiconductor diode that can emit a laser with a wavelength of about 800 nm. But to create a green laser, one must project the other 800 nm wavelength onto a neodimode crystal to convert it to an infrared beam with a wavelength of more than 1,000 nm. Finally, the beam is then projected through a special type of crystal to turn into a green laser with a shorter wavelength.

It is obvious that the process and materials for making red lasers are much simpler than green lasers and certainly with other lasers. So red lasers are the most economically viable option to produce in large quantities and to be used in everyday life.

However, in reality, consumers are increasingly interested in green laser products. With the strong point of being the most capable of lighting, there is no doubt that green laser products become popular and gradually replace red lasers.

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