Why is laser usually only red?

What do you think of when you think of the “laser” beam? Barcode scanners? Or laser pointer used in presentations?

There is one thing in common between these devices, which is only red laser projection. But while the spectrum of light has “trillion” colors, along with the six primary colors, does lasers only have red?

Oh no, if you think that there is only red laser, you are completely wrong. Up to now, humans have been able to create many different colors of lasers by adjusting the wavelength of this type of beam.

Why is laser usually only red?
The difference between the colors of the laser lies in the wavelength.

It’s like asking “How many numbers are on the number line? ” so the answer is infinity . But in fact, until now, humans have only applied lasers with basic colors including red, green, blue and yellow.

The difference between the colors of the laser lies in the wavelength , with the red laser having the longest wavelength (about 630 – 680 nm). Green lasers have a shorter wavelength (532 nm), but are 10-50 times brighter than red lasers and can shine as far as 4.8 km, so they are often used at construction sites.

The wavelength of the blue laser is 445 nm, but if you think that the blue laser will shine brighter than the green, unfortunately that inference is not correct. We see green lasers brighter because the human eye is most sensitive to this color wavelength. The blue laser only allows the light to be more concentrated, which means it has a higher burning potential.

Why is laser usually only red?
There are countless types of lasers with different colors.

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

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

Simply put, because it’s the easiest laser to create.

To have a red laser, one only needs to use a standard semiconductor diode that can emit a laser with a wavelength of about 800 nm. But to make a green laser, one must shine the other 800nm wavelength on a crystal of neodymium to convert it into an infrared beam with a wavelength of more than 1000 nm. Finally, this beam is again shined through a special type of crystal to turn into a green laser with a shorter wavelength.

Obviously the process and also the materials to make a red laser is much simpler than with a green laser and certainly with other lasers as well. So the red laser is the most economical choice for mass production and for devices in our daily life.

However, in fact, today, consumers are gradually paying more attention to and choosing green laser products. With the strength of the ability to illuminate the most, there is no doubt that green laser products become popular and gradually replace red lasers.