Why are the most red laser pointers?

Most of us deal with lasers at some point, the accountant uses it in the store to scan the code on the item you buy, the teacher uses it to attract students' attention to specific points in the presentation, and cat owners use it to play with their cats and film them in nice videos on YouTube, the most popular way to use lasers.

Why the most red laser pointers - the best choice for the most common quantitative production in stores - are the diode-based lasers 

We used to have that red spot in so many areas of life, which makes us think, why red? Natural light consists of 7 colors that decompose when it passes through the prism, do laser pointers give us one of those seven colors?

In short, it's easier to produce laser pointers that emit red light than any other color, and laser pointers are already made in other colors, but red laser indicators remain the best economically, and therefore the best choice for the most common quantitative production in stores.

But why is producing red laser indicators cheaper than others? To understand this, let's see what laser pointers work and how they work.

 

What's the laser?

Laser is a highly concentrated light source, amplified by brightness, in fact laser is an abbreviation for the words "amplifying light by radiation-generated emission".

The laser is emitted when electrons activate certain materials such as glass, crystal and diamonds. By absorbing energy from the electric current, active electrons that have gained energy jump from a lower energy level to a higher energy level in the atom, and when they return to their original state, the energy is released into photons. All the electrons released in this interaction tend to be coherent, i.e. the peaks and bottoms of each wavelength of light are bound together, so they acquire the same color.

Raised electrons release energy in the form of photons with a specific wavelength, creating a bright monochrome light

Raised electrons release energy in the form of photons with a specific wavelength, creating a bright monochrome light

The higher the glass or crystal, the greater the number of active electrons, known as the pumping process. Electrons move at a higher energy level, then return to the original level, pumping more energy, creating successive amounts of light, known as stimulated emission, and then directing this energy to a certain point, becoming a laser light.

Who invented the laser?

The physicist Theodore Maiman created the first laser beam while working at Hughes Research Laboratories in Malibu in 1960, and Mayman used a silver-coated sapphire rod at both ends, cut in a way that allowed the beam of light to bounce inside, producing brightness before coming out of the other end, releasing a bright, narrow beam of light with a 694 nm wave length.

Laser inventor Theodore Mayman

Lasers soon became a well-known product and were (a solution to a problem we have not yet found), scientists had not discovered the enormous potential of this invention, and the Physical Review Letters rejected its research paper at the time, while Nature agreed to publish the discovery that later led to the so-called "laser revolution".

How do different laser pointers work?

Scientists use multiple methods of laser production in different colors, red lasers are exported using a simple semi-conductive diode for light release, consisting of two types of semiconductors placed on top of the other, the upper type usually of gallium arsenic, a poor electron-type semi-conductive material called a p-type conductor, and the lower type of gallium arsenic with selenium, an electron-rich substance called n-type semiconductor. These two articles are fixed together in a diode, thus forming a p-n link.

When the current passes through the p-n link, the electrons from the semi-conductor trigger the type p and fill the holes in the n-type semiconductor, if the p-n link is covered with a layer of silver, the electrons raised release the photons that are confined In the p-n link, it continues to hit that silver-covered surface, and as we explained earlier, the reflection occurs in the p-n link, leading to the induced emission, and the laser light emerges from the link.

Why more red laser pointers?

The laser emanating from the semi-conductive diode in these indicators tends to be in the wavelength range of 700-800 nm, i.e. its color is in the field between orange and red.

Scientists have suggested that the laser should not be red but green, to be a distinct light source for the human eye, because its glow is brighter and can reach greater distances than red lasers, but in order to produce lasers in green color, the wavelength of light pop-up must be less than 600 nm, i.e. shorter than the wavelength of red color, and try to produce a focused beam of light in this wavelength.

The standard semi-conductive diodes emit a laser light with a wave length of about 800 nm, focusing on the nidimium crystal that converts it into an infrared beam with a wave length of about 1,000 nm, and then passes the resulting beam into a dedicated double frequency crystal, turning the beam into a green light with a wavelength of about 540-530 nm.

The refore, the production of green laser light requires some special components, and red laser light is less expensive to produce and remains the most diverse and popular on the market.