Hello steemians and friends, feels good to be back. (Smiles) Welcome to my blog once again.
Lately have you imagined walking into a major store like shoprite and after going round to pick up the items on your long list, then you get to the cashier ready to pay. The cashier smiles at you and starts to manually check for the prices of each items before eventually calculating how much all the items you purchased costs
Imagine how long the queue would be at such stores and how much time would be wasted.
But due to the use of barcode scanner which makes use of laser technology, all the cashier has to do is scan the barcode of each item which converts the printed barcode into a number that the computer understands and the price automatically displays.All this happens super-fast.
Today I would be writing about this unique cutting edge science known as Laser.
Honestly it doesn’t come as a surprise to me that a lot of people associate Lasers with futuristic warfare and sleek spaceships after watching science fiction blockbuster movies like Star Wars and star trek. But there is so much more to lasers because with the advancement of technology some of these equipment are now a reality because scientists have relentlessly continued to transform this science fiction to real life equipment.
Don’t be surprised lasers have been in existence for over half a century and it forms the bedrock of several 21st century digital technology. Nowadays it’s easy to find laser technology been used in Various Every day equipment like DVD players, laser printers, dental drills measuring equipment, eye surgery equipment, tattoo removal, high speed metal cutting machines and without realizing lasers continuously play an important role in our everyday life. Due to the wide range of products that make use of laser technology people now make use of laser technology all day long.
One of the biggest users of laser technology is the military and they make use of lasers in laser guided weapons and missiles. With this laser missiles and weapons enemy equipment can be damaged or destroyed with superb precision compared with other conventional missiles and weapons.
Aside the military A lot of industries employ the use of laser. For instance, in medicine precision is of utmost importance, Lasers are widely used by doctors for various activities such as blasting tumors, correcting problems relating to people’s eyes such as laser eye surgery, fixing detached retinas and cataract treatment and for various other purposes.
In recent times lasers are used in the clothing industry to ensure speed and accuracy during manufacturing of clothes, fabrics are cut by robot guided laser unlike like the days where pieces of cloth had to be cut by hand. This machines can cut several thickness of fabrics at the same time thereby improving efficiency and productivity.
Lasers beams are quite powerful enough to cut through lumps of metals so Major industries widely make use of carbon dioxide laser for their cutting tools for precision as well as easy automation and these tools do not require sharpening. Also In digital communication Lasers are widely used along with fiber optics cables for a technology known as photonics which refers to using photons of light to communicate. This involves sending data back and forth over the Internet
Now let’s take a closer look at this unique cutting edge science….
Laser is a short form for Light Amplification by stimulated Emission of Radiation. As the name implies Laser is a device that controls the way energized atoms release photons. Typically, a laser is simply a machine that forms a concentrated light beam by making billions of atoms pump out trillions of photons (known as light particles) all at once, due to this the photons line up and become really concentrated.
Lasers are precise, powerful and amazingly useful beam of energy. Lasers are much more than just powerful flashlight and If you closely observe a laser and a flashlight you would realize two major differences immediately.
A flashlight would produce a mixture of all different colors known as “white” light which is made by light waves of different frequencies. While Lasers would produce monochromatic light which is a single precise frequency and a specific wavelength of light (color) mostly bright red or green or sometimes an invisible color such as infrared or ultraviolet
Compared with a flashlight beam lasers are very directional and this is due to a tighter and narrower beam, which makes lasers very strong and concentrated over a longer distance. However, in the case of a flashlight the beam spreads out through the lens into a really short and relatively fuzzy cone thereby making the light very weak.
But aside this two features you could have easily noticed, there is a more important difference:
In the case of flashlight beams light waves are all jumbled up such that the crests of some of the beams are mixed with the troughs of others while in the case of lasers the waves are coherent and all the photons have a wave fronts that lunch in unison such that the crest of every wave is lined up with the crest of every other wave. For this to occur stimulated emissions has to occur so photon emission is organized.
Several types of lasers exist and they all have different and essential features but generally a laser requires two major parts to function.
Firstly, it requires the Lasing medium which is a load of atoms with electrons in them that can be stimulated. The atoms could either be solid, liquid or gas. For the laser to work effectively a large collection of atoms must be in an excited state.
Secondly The laser would require something that would be used to stimulate the atom like a flash tube or another laser to get the atom into an excited state
Let’s take a brief look at the different kinds of Lasers
Since different kind of atoms can be excited through different kind of ways, the five major kinds of lasers are solid-state, liquid dye, gas, semiconductor and fiber.
For Solid-state lasers their medium is like a ruby rod (or sometimes other solid crystalline material) with a flash tube around it to pump its atoms to full energy to produce high powered beams in very brief pulses.
While Gas lasers produce continuous bright beams using compounds of noble gas or carbon dioxide as their medium pumped by electricity.
In the case of a liquid dye laser, organic dye molecules are used as the medium and they are pumped by an arc lamp, a flash lamp or another laser. Due to this liquid dye laser have a major advantage because they can be used to produce a broader band of light frequencies more than the solid state laser and the gas laser.
For fiber lasers, they function inside an optical fiber, thereby making a doped fiber optics cable to become the amplifying medium. This makes them efficient, powerful and it’s easier to direct laser light to points where it is needed.
Solid, liquid, gas lasers are quite powerful, expensive and large. However, semiconductor lasers look similar to chip like devices and they are cheaper and tiny. They are used in barcode scanner, CD players, laser printers.
How laser operates.
When Electrical discharges pump the lasing medium, it creates excited state atoms. Generally, the atoms are excited to two or three levels above ground state such that the degree of population inversion is increased (the number of atoms in ground state versus the number of atoms in excited state)
The excited electrons absorbed some amount of energy to get to the excited state, so energy of the excited electron is greater than the electrons in ground state and the electron can also release the energy. This energy emitted comes in the form of light energy known as photons. Photons with identical wavelength can be released by two identical atoms with electrons in identical state.
At this point a process called absorption takes place, which is a process where atoms absorb energy when the electrons in them jump from a higher energy level. The atoms absorb this energy and after a few milliseconds they give off a photon of light when the electrons return back to their original energy level.
As this process occurs stimulated emission continuously happens within the medium, such that one of the photons stimulates or induces atomic emission in an already excited atom and when this occurs a photon that has the same frequency and direction of the incoming photon is given off by the excited atom and the original photon is still intact, so one photon of light has produced two. The stimulated emission of radiation causes an increase in the amount of light within the medium such that the light is amplified.
For the laser tube to keep bouncing back and forth within the laser medium, a pair of mirror is used. A mirror is placed at one end of the laser tube, while a partial mirror is placed at the other end. So as photons with specific wavelength gets reflected off the mirror and travel back and forth within the lasing medium, they continuously stimulate other electrons to make the downward energy jump thereby causing the emission of more photons of the same wavelength and phase.
As this process continues a cascade effect occurs and in short while many photons of the same wavelength and phase have been propagated.
However, the partial mirror bounces some photons back into the medium but also let’s some of the photons escape. A Very concentrated beam of powerful laser light is now formed by the escaping photons.
Lasers are precise, powerful and amazingly useful beam of energy and they are much more than just powerful flashlight. Lasers find use in various everyday equipment as well as more sophisticated equipment, some lasers are very powerful and can cut through steel by melting through the steel as it is focused on it and some lasers are weak and are used in today’s pocket laser pointers.
They range from lasers that cannot emit laser radiation at known hazard levels to high power lasers which are hazardous.
There you have it …. Lasers