The main difference between Laser and Light is that Laser is referred to as coherent, monochromatic, and highly directional light, whereas light is referred to as incoherent and divergent because of the mixture of the electromagnetic waves that contain different wavelengths.
Laser
Any of several devices that emit highly amplified and coherent radiation of one or more discrete wavelengths. One of the most common lasers makes use of atoms in a metastable energy state, which, as they decay to a lower energy level, stimulate others to decay, resulting in a cascade of emitted radiation.
Light
Electromagnetic radiation that is visible, perceivable by the normal human eye as colors between red and violet, having frequencies between 400 terahertz and 790 terahertz and wavelengths between 750 nanometers and 380 nanometers. Also called visible light.
Laser
A beam of radiation emitted by a laser.
Light
Electromagnetic radiation of any frequency or wavelength.
Laser
(Sports)A ball or puck sent in a straight line at high speed
Shot a laser into the upper right corner of the goal.
Light
The sensation of perceiving light; brightness
A sudden light that made me blink.
Laser
A device that produces a monochromatic, coherent beam of light.
Light
A source of light, especially a lamp, a lantern, or an electric lighting fixture
Turn out the lights when you leave.
Laser
A beam of light produced by such a device; a laser beam.
Light
The illumination derived from a source of light
By the light of the moon.
Light
The particular quantity or quality of such illumination
Moved the lamp closer to get better light.
Laser
A gum resin obtained from certain umbelliferous plants.
Light
The pathway or route of such illumination to a person
You're standing in his light.
Light
A source of fire, such as a match or cigarette lighter.
Laser
To cut with a laser.
Light
A mechanical device that uses illumination as a signal or warning, especially a beacon or traffic signal.
Laser
(sports) To throw or kick with laser-like precision.
Laser
A device which produces an intense, usually narrow, monochromatic beam of coherent light; called also optical maser. It has various forms, and is used in various applications in science and technology. The beam is produced by boosting the majority of the electrons in specific radiation-absorbing atoms in a medium into a higher energy level, from which they are stimulated by their own emitted radiation to drop back synchronously to their lower energy level, and emit light which is in phase (coherent).
Laser
An acronym for light amplification by stimulated emission of radiation; an optical device that produces an intense monochromatic beam of coherent light
Light
Something, such as a window, that admits illumination.
Light
(Architecture) One of two or more openings in a window divided by a mullion or mullions.
Light
Something that provides information or clarification
Research that produced little new light on the question.
Light
A state of awareness or understanding, especially as derived from a particular source
In the light of experience.
Light
Public attention; general knowledge
Brought the scandal to light.
Light
Spiritual awareness; illumination.
Light
A way of looking at or considering a matter; an aspect
Saw the situation in a different light.
Light
Lights One's individual opinions, choices, or standards
Acted according to their own lights.
Light
A person who inspires or is adored by another
My daughter is the light of my life.
Light
A prominent or distinguished person; a luminary
One of the leading lights of the theater.
Light
An expression of the eyes
A strange light in her eyes.
Light
Lights Pieces of laundry that are not dark in color.
Light
Light In Quaker doctrine, the guiding spirit or divine presence in each person.
Light
To set on fire; ignite or kindle
Lit the kindling.
Light
To cause to give out light; make luminous
Lit a lamp.
Light
To provide, cover, or fill with light; illuminate
Fireworks lighting the sky.
Light
To signal, direct, or guide with light
"You'd ... set the lamp in the dormer window to light him home through the storm" (Edith Nesbit).
Light
To enliven or animate
A smile lit her face.
Light
To start to burn; be ignited or kindled
Green wood does not light easily.
Light
To emit light; be lighted
Wait until the indicator lights up.
Light
To get down, as from a vehicle or horse; dismount.
Light
To descend to the ground after flight; land.
Light
To come upon one unexpectedly
Misfortune lighted upon him.
Light
To come upon by chance or accident. Used with on or upon
Lit on the perfect solution to the problem.
Light
Having a greater rather than lesser degree of lightness.
Light
Of or being an additive primary color.
Light
Characterized by or filled with light; bright
A room that is light when the shutters are open.
Light
Not dark in color; fair
Light hair and skin.
Light
Served with milk or cream. Used of coffee.
Light
Of relatively little weight; not heavy
A light load.
Light
Of relatively little weight for its size or bulk
Balsa is a light wood.
Light
Of less than the correct, standard, or legal weight
A light pound.
Light
Designed for ease and quickness of movement; having a structure that is slim and has little weight for its type or class
Light aircraft.
Light
Designed to carry relatively little weight
Light trucks.
Light
Carrying little equipment or armament
Light cavalry.
Light
Requiring relatively little equipment and using relatively simple processes to produce consumer goods
Light industry.
Light
Exerting little force or impact; gentle
A light pat.
Light
Indistinct; faint
Light print that I could barely make out.
Light
Low in quantity or intensity
Light traffic.
Light snow.
Light
Consuming or using relatively moderate amounts; abstemious
A light eater.
A light smoker.
Light
Not harsh or severe
Gave the offender a light sentence.
Light
Moving easily and quickly; nimble
You're very light on your feet.
Light
Easy to perform or accomplish; requiring little effort
Light chores.
Light
Easy to bear or endure
A light tax.
Light
Having little importance; insignificant
Light conversation.
Light
Intended primarily as entertainment and lacking serious or weighty content
A light comedy.
Light
Not solemn or serious
Spoke in a light manner of the situation.
Light
Free from worries or troubles; blithe
A light heart.
Light
Mildly dizzy or faint
Felt light in the head.
Light
Easily awakened or disturbed
A light sleeper.
Light
Easily digested
A light supper.
Light
Containing a relatively small amount of a potentially harmful ingredient, such as alcohol, fat, or sodium
Light beer.
Light mayonnaise.
Light
Having a spongy or flaky texture; well-leavened
Light pastries.
Light
Having a loose, porous consistency
Light soil.
Light
Of, relating to, or being a syllable ending in a short vowel or a short vowel plus a consonant.
Light
Of, relating to, or being a vowel or syllable pronounced with little or no stress.
Light
In a light manner; lightly.
Light
With little weight and few burdens
Traveling light.
Light
Visible electromagnetic radiation. The human eye can typically detect radiation (light) in the wavelength range of about 400 to 750 nanometers. Nearby shorter and longer wavelength ranges, although not visible, are commonly called ultraviolet and infrared light.
As you can see, this spacious dining-room gets a lot of light in the mornings.
Light
A source of illumination.
Put that light out!
Light
(figurative) Spiritual or mental illumination; enlightenment, useful information.
Can you throw any light on this problem?
Light
Facts; pieces of information; ideas, concepts.
Light
A notable person within a specific field or discipline.
Picasso was one of the leading lights of the cubist movement.
Light
(painting) The manner in which the light strikes a picture; that part of a picture which represents those objects upon which the light is supposed to fall; the more illuminated part of a landscape or other scene; opposed to shade.
Light
A point of view, or aspect from which a concept, person or thing is regarded.
I'm really seeing you in a different light today.
Magoon's governorship in Cuba was viewed in a negative light by many Cuban historians for years thereafter.
Light
A flame or something used to create fire.
Hey, buddy, you got a light?
Light
A firework made by filling a case with a substance which burns brilliantly with a white or coloured flame.
A Bengal light
Light
A window in architecture, carriage design, or motor car design: either the opening itself or the window pane of glass that fills it, if any.
This facade has eight south-facing lights.
Light
The series of squares reserved for the answer to a crossword clue.
The average length of a light on a 15×15 grid is 7 or 8.
Light
(informal) A cross-light in a double acrostic or triple acrostic.
Light
Open view; a visible state or condition; public observation; publicity.
Light
The power of perception by vision.
Light
The brightness of the eye or eyes.
Light
A traffic light, or, by extension, an intersection controlled by one or more that will face a traveler who is receiving instructions.
To get to our house, turn right at the third light.
Light
(curling) A stone that is not thrown hard enough.
Light
A low-alcohol lager.
Light
(transitive) To start (a fire).
We lit the fire to get some heat.
Light
(transitive) To set fire to; to set burning.
She lit her last match.
Light
(transitive) To illuminate; to provide light for when it is dark.
I used my torch to light the way home through the woods in the night.
Light
(intransitive) To become ignited; to take fire.
This soggy match will not light.
Light
To attend or conduct with a light; to show the way to by means of a light.
Light
To make (a bonus) available to be collected by hitting a target, and thus light up the feature light corresponding to that bonus to indicate its availability.
Light' the extra ball by amassing 500 million points in the wizard mode.
Light
(nautical) To unload a ship, or to jettison material to make it lighter
Light
To lighten; to ease of a burden; to take off.
Light
To find by chance.
I lit upon a rare book in a second-hand bookseller's.
Light
To stop upon of eyes or a glance; to notice
Light
(archaic) To alight; to land or come down.
She fell out of the window but luckily lit on her feet.
Light
Having light; bright; clear; not dark or obscure.
The room is light when the Sun shines through the window.
Light
Pale or whitish in color; highly luminous and more or less deficient in chroma.
She had light skin.
Light
(of coffee) Served with extra milk or cream.
I like my coffee light.
Light
Having little or relatively little actual weight; not cumbrous or unwieldy.
A light load ; a lighter backpack after having removed the books ; light weapons
Light
Having little weight as compared with bulk; of little density or specific gravity.
Feathers and cork are light ; oil is lighter than water
Light
Of short or insufficient weight; weighing less than the legal, standard, or proper amount; clipped or diminished.
To issue light coin
Light
Lacking that which burdens or makes heavy.
Light
Free from burden or impediment; unencumbered.
Light
Lightly built; typically designed for speed or small loads.
A light aircraft ; a light tank
Light
(military) Not heavily armed; armed with light weapons.
Light infantry; a troop of light horse
Light
Riding high because of no cargo; by extension, pertaining to a ship which is light.
If a ship is light or partially loaded ; the light draft of a vessel, or its light displacement
Light
Without any piece of equipment attached or attached only to a caboose.
The light locomotives ; a locomotive may be moved light
Light
(cookery) Not heavy or soggy; spongy; well raised.
A light bread ; sponge cake is a light cake
Light
Low in fat, calories, alcohol, salt, etc.
This light beer still gets you drunk if you have enough of it.
Light
Slight, not forceful or intense; small in amount or intensity.
A light drizzle; a light rain was falling; a light snow set in
Light
Gentle; having little force or momentum.
This artist clearly had a light, flowing touch.
Light
Easy to endure or perform.
Light duties around the house
Light
Unimportant, trivial, having little value or significance.
I made some light comment, and we moved on.
Light
(obsolete) Unchaste, wanton.
Light
Not encumbered; unembarrassed; clear of impediments; hence, active; nimble; swift.
Light
(dated) Easily influenced by trifling considerations; unsteady; unsettled; volatile.
A light, vain person; a light mind
Light
Indulging in, or inclined to, levity; lacking dignity or solemnity; frivolous; airy.
Ogden Nash was a writer of light verse.
Light
Not quite sound or normal; somewhat impaired or deranged; dizzy; giddy.
Light
Easily interrupted by stimulation.
Light sleep; light anesthesia
Light
Carrying little.
I prefer to travel light.
Light
That agent, force, or action in nature by the operation of which upon the organs of sight, objects are rendered visible or luminous.
Light
That which furnishes, or is a source of, light, as the sun, a star, a candle, a lighthouse, etc.
Then he called for a light, and sprang in.
And God made two great lights; the greater light to rule the day, and the lesser light to rule the night.
Light
The time during which the light of the sun is visible; day; especially, the dawn of day.
The murderer, rising with the light, killeth the poor and needy.
Light
The brightness of the eye or eyes.
He seemed to find his way without his eyes;For out o'door he went without their helps,And, to the last, bended their light on me.
Light
The medium through which light is admitted, as a window, or window pane; a skylight; in architecture, one of the compartments of a window made by a mullion or mullions.
There were windows in three rows, and light was against light in three ranks.
Light
Life; existence.
O, spring to light, auspicious Babe, be born !
Light
Open view; a visible state or condition; public observation; publicity.
The duke yet would have dark deeds darkly answered; he would never bring them to light.
Light
The power of perception by vision.
My strength faileth me; as for the light of my eyes, it also is gone from me.
Light
That which illumines or makes clear to the mind; mental or spiritual illumination; enlightenment; knowledge; information.
He shall never knowThat I had any light of this from thee.
Light
Prosperity; happiness; joy; felicity.
Then shall thy light break forth as the morning, and thy health shall spring forth speedily.
Light
The manner in which the light strikes upon a picture; that part of a picture which represents those objects upon which the light is supposed to fall; the more illuminated part of a landscape or other scene; - opposed to shade. Cf. Chiaroscuro.
Light
Appearance due to the particular facts and circumstances presented to view; point of view; as, to state things fairly and put them in the right light.
Frequent consideration of a thing . . . shows it in its several lights and various ways of appearance.
Light
One who is conspicuous or noteworthy; a model or example; as, the lights of the age or of antiquity.
Joan of Arc,A light of ancient France.
Light
A firework made by filling a case with a substance which burns brilliantly with a white or colored flame; as, a Bengal light.
Lord, lift thou up the light of thy countenance upon us.
Light
Having light; not dark or obscure; bright; clear; as, the apartment is light.
Light
White or whitish; not intense or very marked; not of a deep shade; moderately colored; as, a light color; a light brown; a light complexion.
Light
Having little, or comparatively little, weight; not tending to be the center of gravity with force; not heavy.
These weights did not exert their natural gravity, . . . insomuch that I could not guess which was light or heavy whilst I held them in my hand.
Light
Not burdensome; easy to be lifted, borne, or carried by physical strength; as, a light burden, or load.
Ye shall find rest unto your souls. For my yoke is easy, and my burden is light.
Light
Easy to be endured or performed; not severe; not difficult; as, a light affliction or task.
Light sufferings give us leisure to complain.
Light
Easy to be digested; not oppressive to the stomach; as, light food; also, containing little nutriment.
Light
Not heavily armed; armed with light weapons; as, light troops; a troop of light horse.
Light
Not encumbered; unembarrassed; clear of impediments; hence, active; nimble; swift.
Unmarried men are best friends, best masters . . . but not always best subjects, for they are light to run away.
Light
Not heavily burdened; not deeply laden; not sufficiently ballasted; as, the ship returned light.
Light
Slight; not important; as, a light error.
Light
Well leavened; not heavy; as, light bread.
Light
Not copious or heavy; not dense; not inconsiderable; as, a light rain; a light snow; light vapors.
Light
Not strong or violent; moderate; as, a light wind.
Light
Not pressing heavily or hard upon; hence, having an easy, graceful manner; delicate; as, a light touch; a light style of execution.
Light
Easy to admit influence; inconsiderate; easily influenced by trifling considerations; unsteady; unsettled; volatile; as, a light, vain person; a light mind.
There is no greater argument of a light and inconsiderate person than profanely to scoff at religion.
Light
Indulging in, or inclined to, levity; wanting dignity or solemnity; trifling; gay; frivolous; airy; unsubstantial.
Seneca can not be too heavy, nor Plautus too light.
Specimens of New England humor laboriously light and lamentably mirthful.
Light
Not quite sound or normal; somewhat impaired or deranged; dizzy; giddy.
Are his wits safe? Is he not light of brain ?
Light
Easily bestowed; inconsiderately rendered.
To a fair semblance doth light faith annex.
Light
Wanton; unchaste; as, a woman of light character.
A light wife doth make a heavy husband.
Light
Not of the legal, standard, or usual weight; clipped; diminished; as, light coin.
Light
Loose; sandy; easily pulverized; as, a light soil.
Light
To set fire to; to cause to burn; to set burning; to ignite; to kindle; as, to light a candle or lamp; to light the gas; - sometimes with up.
If a thousand candles be all lighted from one.
And the largest lamp is lit.
Absence might cure it, or a second mistressLight up another flame, and put out this.
Light
To give light to; to illuminate; to fill with light; to spread over with light; - often with up.
Ah, hopeless, lasting flames! like those that burnTo light the dead.
One hundred years ago, to have lit this theater as brilliantly as it is now lighted would have cost, I suppose, fifty pounds.
The sun has set, and Vesper, to supplyHis absent beams, has lighted up the sky.
Light
To attend or conduct with a light; to show the way to by means of a light.
His bishops lead him forth, and light him on.
Light
To become ignited; to take fire; as, the match will not light.
Light
To be illuminated; to receive light; to brighten; - with up; as, the room light up very well.
Light
To lighten; to ease of a burden; to take off.
From his head the heavy burgonet did light.
Light
To dismount; to descend, as from a horse or carriage; to alight; - with from, off, on, upon, at, in.
When she saw Isaac, she lighted off the camel.
Slowly rode across a withered heath,And lighted at a ruined inn.
Light
To feel light; to be made happy.
It made all their hearts to light.
Light
To descend from flight, and rest, perch, or settle, as a bird or insect.
[The bee] lights on that, and this, and tasteth all.
On the tree tops a crested peacock lit.
Light
To come down suddenly and forcibly; to fall; - with on or upon.
On me, me only, as the source and springOf all corruption, all the blame lights due.
Light
To come by chance; to happen; - with on or upon; formerly with into.
The several degrees of vision, which the assistance of glasses (casually at first lit on) has taught us to conceive.
They shall light into atheistical company.
And here we lit on Aunt Elizabeth,And Lilia with the rest.
Light
(physics) electromagnetic radiation that can produce a visual sensation;
The light was filtered through a soft glass window
Light
Any device serving as a source of illumination;
He stopped the car and turned off the lights
Light
A particular perspective or aspect of a situation;
Although he saw it in a different light, he still did not understand
Light
The quality of being luminous; emitting or reflecting light;
Its luminosity is measured relative to that of our sun
Light
An illuminated area;
He stepped into the light
Light
A condition of spiritual awareness; divine illumination;
Follow God's light
Light
The visual effect of illumination on objects or scenes as created in pictures;
He could paint the lightest light and the darkest dark
Light
A person regarded very fondly;
The light of my life
Light
Mental understanding as an enlightening experience;
He finally saw the light
Can you shed light on this problem?
Light
Having abundant light or illumination;
They played as long as it was light
As long as the lighting was good
Light
Public awareness;
It brought the scandal to light
Light
Brightness and animation of countenance;
He had a sparkle in his eye
Light
A divine presence believed by Quakers to enlighten and guide the soul
Light
A visual warning signal;
They saw the light of the beacon
There was a light at every corner
Light
A device for lighting or igniting fuel or charges or fires;
Do you have a light?
Light
Make lighter or brighter;
This lamp lightens the room a bit
Light
Begin to smoke;
After the meal, some of the diners lit up
Light
To come to rest, settle;
Misfortune lighted upon him
Light
Cause to start burning; subject to fire or great heat;
Great heat can ignite almost any dry matter
Light a cigarette
Light
Fall to somebody by assignment or lot;
The task fell to me
It fell to me to notify the parents of the victims
Light
Of comparatively little physical weight or density;
A light load
Magnesium is a light metal--having a specific gravity of 1.74 at 20 degrees C
Light
(used of color) having a relatively small amount of coloring agent;
Light blue
Light colors such as pastels
A light-colored powder
Light
Of the military or industry; using (or being) relatively small or light arms or equipment;
Light infantry
Light cavalry
Light industry
Light weapons
Light
Not great in degree or quantity or number;
A light sentence
A light accent
Casualties were light
Light snow was falling
Light misty rain
Light smoke from the chimney
Light
Psychologically light; especially free from sadness or troubles;
A light heart
Light
Characterized by or emitting light;
A room that is light when the shutters are open
The inside of the house was airy and light
Light
Used of vowels or syllables; pronounced with little or no stress;
A syllable that ends in a short vowel is a light syllable
A weak stress on the second syllable
Light
Easily assimilated in the alimentary canal; not rich or heavily seasoned;
A light diet
Light
(used of soil) loose and large-grained in consistency;
Light sandy soil
Light
(of sound or color) free from anything that dulls or dims;
Efforts to obtain a clean bass in orchestral recordings
Clear laughter like a waterfall
Clear reds and blues
A light lilting voice like a silver bell
Light
Moving easily and quickly; nimble;
The dancer was light and graceful
A lightsome buoyant step
Walked with a light tripping step
Light
Demanding little effort; not burdensome;
Light housework
Light exercise
Light
Of little intensity or power or force;
The light touch of her fingers
A light breeze
Light
(physics, chemistry) not having atomic weight greater than average;
Light water is ordinary water
Light
Weak and likely to lose consciousness;
Suddenly felt faint from the pain
Was sick and faint from hunger
Felt light in the head
A swooning fit
Light-headed with wine
Light-headed from lack of sleep
Light
Very thin and insubstantial;
Thin paper
Flimsy voile
Light summer dresses
Light
Marked by temperance in indulgence;
Abstemious meals
A light eater
A light smoker
Ate a light supper
Light
Less than the correct or legal or full amount often deliberately so;
A light pound
A scant cup of sugar
Regularly gives short weight
Light
Having little importance;
Losing his job was no light matter
Light
Intended primarily as entertainment; not serious or profound;
Light verse
A light comedy
Light
Silly or trivial;
Idle pleasure
Light banter
Light idle chatter
Light
Having a spongy or flaky texture; well-leavened;
Light pastries
Light
Designed for ease of movement or to carry little weight;
Light aircraft
A light truck
Light
Having relatively few calories;
Diet cola
Light (or lite) beer
Lite (or light) mayonnaise
A low-cal diet
Light
(of sleep) easily disturbed;
In a light doze
A light sleeper
A restless wakeful night
Light
Casual and unrestrained in sexual behavior;
Her easy virtue
He was told to avoid loose (or light) women
Wanton behavior
Light
With few burdens;
Experienced travellers travel light
The waves which came into existence because of the vibrations that occur between an electric field and a magnetic field are called electromagnetic waves. Both the laser and the light are considered as the electromagnetic waves. Because of this reason, they travel in a vacuum with the velocity of light. Nevertheless, laser light has properties that are very unique and cannot be seen in nature. Thus, it is considered to have very important properties.
Laser and light are frequently used in physics and are considered as the two important terms of this discipline of science. Sometimes we take laser as the form of the light. But the reality is that it is a light amplification of the radiations which are stimulated at the time of their emissions. We generally consider laser and light as the traveling photons. Both of them are different from each other in various ways.
We mainly differentiate laser and the light through the terms of the coherence. The laser is suggested as the monochromatic, coherent, and the unidirectional beam of light. Light present in the normal incandescent bulbs, on the flip side, emit photons according to their path of traveling, wavelengths, and their polarization. The laser is referred to as intense light, whereas ordinary light is not considered as an intense light.
Furthermore, the principle on which laser is based is stimulated emissions in which the photons get stimulated, and they emit photons on returning to their original energy states. Light, on the other hand, has a direction of travel and also has a whole range of energies. A laser is considered to be the type of electromagnetic wave which has a very specific color. Light, on the other side, is considered to be the type of electromagnetic wave, which is the sum of all the colors.
The term “LASER” is an abbreviation for the Light Amplification by the Stimulated Emission of Radiation. Mostly atoms remain in the ground state because it is a stable state. Nevertheless, there also exists a small percentage of the atoms which are present at the excited or higher energy states. It is the temperature on which the percentage of the atoms at higher energy states depend. The number of atoms present at a given excited energy level increases as the temperature increases.
The lifespan of the excited state of the atoms is very short because of their instability. As a result, the excited atoms release their excess energy as photons and immediately de-excite to their ground states. These transitions do not demand any stimulus from outside and hence are called the probabilistic transitions. It is impossible to estimate the time that when an excited atom or molecule is getting de-excited. The transition process and the emission of the photons are random. We can say that the emission is spontaneous, and the emission of photons during transitions is out of phase (incoherent).
Nevertheless, some of the materials comprise higher energy states that have higher lifetimes. That energy states are called as the metastable states. Therefore, the atoms or molecules present in this state do not come back to their ground state immediately. We can also pump atoms or molecules to their metastable states by providing energy to them from the outside. They remain in the metastable state for a long time without returning to the ground. As a result, we can largely increase the percentage of the atoms at the metastable state by pushing more atoms or molecules from the ground state to the metastable state. This situation is called population inversion because it is completely opposite to the normal situation.
However, we can stimulate an atom to de-excite in a metastable state by an incident photon. A new photon is released during the transition. If the energy of the incoming photon is exactly equal to the difference of the energy between the ground state and the metastable state, then the frequency of the new photon, energy, the phase, and the direction will be the same to those of the incident photon. The new photon will be able to stimulate another excited atom if the population inversion state is the material medium. Ultimately, the process will convert into a chain reaction that will be responsible for emitting a flood of identical photons.
The emitted photons are monochromatic (single color), coherent (in-phase), and directional. We called this action as the basic laser action. The narrow frequency range, coherence, and directionality are some unique properties of laser light and are considered as the key advantages which are used in the laser applications. There are various types of lasers according to the type of lasing mediums, like gas lasers, dye lasers, solid-state lasers, and semiconductor lasers. We are using lasers in many different applications, and various new applications are being developed.
The fluorescent bulbs, the incandescent bulbs, which are also called the Tungsten filament bulbs and mainly the sunlight, are the most useful sources of ordinary light. According to theories, we came to know that any object having a temperature greater than the 0K (absolute zero) emits electromagnetic radiation. This is referred to as the basic concept that is being used in the incandescent bulbs. There is a Tungsten filament in an incandescent bulb.
When we switch on the bulb, then the applied potential difference enables the electrons to accelerate. As we all know that Tungsten has a high electrical resistance, therefore, the electrons collide with atomic cores within the shorter expanses. Because of the electron- atomic core collisions, they are involved in transferring some of their energy to the atomic cores, as the momentum of the electrons gets the change because of the collision. As a result of this transfer of energy, the Tungsten filament heats up.
The heated filament is involved in emitting the electromagnetic waves, which cover a wide range of frequency and turns into a blackbody. It is responsible for emitting IR, visible waves, microwaves, etc. But the useful part of this spectrum is its visible part. The sun is referred to as a super-heated blackbody. Because of this reason, it is involved in emitting a tremendous amount of energy, which is in the form of electromagnetic waves and is responsible for covering a wide range of frequency from radio waves to gamma rays. It is suggested that any heated body that emits radiation also emits the light waves.
At a given temperature, the Wien’s displacement law gives the wavelength which corresponds to the highest intensity of a blackbody. According to this law, the wavelength which corresponds to the highest intensity decreases as we increase the temperature. The wavelength which corresponds to the highest intensity of an object is considered to fall into the IR region at room temperature. Nevertheless, we can adjust the wavelength corresponding to the highest intensity by increasing the temperature of the body. But, the emission of the electromagnetic waves having other frequencies cannot be stopped. Because of this reason, such waves are not considered monochromatic.
It is obvious that all the ordinary light sources are referred to as divergent. Normally, we can say that ordinary light sources are involved in emitting the electromagnetic waves in all directions randomly. The phases of the emitted photons do not have any relationship. So, they are incoherent light sources. The waves emitted by the ordinary light sources are generally considered as polychromatic.
