Stimulated Emission

[@sebastianfullerstarroman5554]

Very helpful, thank you!!! Much more coherent than my lecturer! (Pun intended)

[@brentsegrist246]

It's very rare to find a video explaining exactly what I want to know, and in such a concise way. Very helpful! Thank you for making it!

[@pavlovshuman3376]

Successfully watched every video on this playlist! Thank you Mr.Anderson. May the mass times acceleration be with you!

[@ayushsharma3988]

I see what you did there🤣

[@premsai6612]

Nah better to say Rate of change of momentum

[@kelvinmoisespuenteperez7326]

EXCELLENT. There is no other way to describe this clear and concise explanation.

[@pranjalvyas1564]

Thank you so much bozeman science I hope you will continue

[@kobedierckx2918]

Nice brief introduction to LASERS.

[@EugeneKhutoryansky]

Nice video.

[@devarya8963]

Shivanshu Siyanwal she herself has great youtube channel for physics videos

[@goodexams3064]

@0:55 why would it fall back down again? Coz it is getting energy continuously.

[@goodexams3064]

@1:24 could you explain why?

[@mrdeath4446]

@@goodexams3064 Bro just know it that's it

[@user-ee8hx1xq9i]

Thank Mr. Anderson and youtube for letting me watch these useful videos for free.

[@soundsofnature2141]

Thank you, perfect explanation. BTW, <a href="#" class="seekto" data-time="37">0:37</a>, you confused atom with electron )

[@bogdanchiritoiubc]

Excellent, most sources miss out on the avalanche effect and how that it developed within a laser.

[@Sam-ko2yn]

In spontanious emission the energy of the emitted photon does not match to the energy level inside the atom. Theory (Wigner Weisskopf) shows that with spontanious emission the probability to get a photon with an certain frequency or polarisation is a lorentzian lineshape shifted slightly from the frequency splitting of the energy levels inside the Atom.

[@dozog]

exactly. I think he got the descriptions of spontaneous and stimulated emission somewhat mixed. You didn't mention the direction of the photon. If i remember correctly, the direction of a spontaneously emitted photon has no preference in the direction of the photon that stimulated it previously. In fact, for the spontaneous emission, it doesn't matter how the electron was excited.

[@mohhitkumarjha3288]

very helpful, and beautifully explained how stimulated emission work

[@merrysanjenbam603]

Short, Simple and Clear! Thanks

[@user-qx3sv9oz9n]

this is better than MIT, cornell open course lectures, not just better but grey color & bright clear color

[@robbieeldoueik2589]

kenny, you are correct. it is the electron that is absorbing the photons energy, however the average energy of the atom itself goes up as well as a result. both can be considered correct. it is also the electron that is giving off the photons, but again, the electron is considered part of the atom so either way you say it is right.

[@Thelightsaver1]

Robbie Eldoueik Well, I think what he says is fine if he clarifies that the atom itself doesn't jump through energy states (despite the "average energy" changing). It's an honest mistake, but misleading nonetheless.

[@khaledalhorani7965]

Incredibly helpful just like all your videos, thanks a billion to the speed of light

[@deekshas3671]

One of the best explanation indeed !! 🙌

[@mavoop]

Great video, short and to the point! Thank you.

[@imranhossainraju7510]

my 3 days hard working through book , u describe in 4 minutes hats off

[@salam7905]

it was incredibly helpful !!

[@HimanshuSingh-df3ml]

Very helpful and really awesome way of teaching.

[@themirage6223]

Sir in case of stimulated emission ,when we give energy why it comes back to the lower energy state instead of going to the next higher energy state?

[@joshdheda8776]

because the higher energy state (if it does exist at all) is highly unstable

[@tofayelkarim]

Nice Explanation.

[@esharani7503]

Very nice explained

[@andrewhurlbut1232]

Bro TYSM. My Physics teacher is dog and this is literally his 45 minute lecture in 3 minutes.

[@reubenwilliammpembe667]

thank you Sir you are the best!!! #RespectFromSouthAfrica

[@horvathbenedek3596]

Thank you, this was a great explanation.

[@mosab643]

Free energy... nice explanation.

[@eieb9087]

excellent demonstration

[@xxx9274]

You are Really Helping Engineering students

[@soubhagyamukherjee1241]

Is the stimulation of atom from lower energy state to upper energy state by Photon called optical pumping?

[@kunalbanerjee2952]

Very informative & crisp. Thanks

[@sashwatyo1293]

Extremely helpful

[@vaishnavijennie2572]

Soooo goooood thank you sir 👍😄

[@akankshayadav1602]

So brilliant explanation sir....... Thank you very much

[@jeyaraman8826]

...Able to Get a clear cut idea about this....Thank u so much!!

[@ilyasshakmaoui3618]

thank you for making it simple to understand

[@varunraajsm9789]

oh man you've finally cleared my doubt

[@amrutvani2]

Why atom at E2 level does not move to E3 level after being hit by a photon ?

[@SogMosee]

+amrutvani2 good question!

[@yasirrahim5501]

amrutvani2 The atoms want to be stable, going to an energy level of E3 will make it even more unstable than it already is so instead it drops to E1 and emits 2 coherent photons.

[@haripanditparanjpe30]

Alternatively I think E3 level is achieved for a transient time which of of course being unstable drops down to E2 and then to E1 , releasing 2 photons. What say ?

[@FlyingJetpack1]

The jump between level 2 and level 3 are different compared to the level 1 to 2, usually the next level requires less energy to reach that state, that means the photon that hit this electron is essentially "overshooting" the needed energy level, therefore it can only go through. But by passing by that excited electron, it stimulates it to be emitted as well.

[@saranshbansal2746]

the electron actually wont move to level E3 because the enrgy of the incident electron is E2-E1 and not E3-E2....for further excitation we need an electron of energy E3-E2 that's why the electron has no option but to relax to ground state

[@bolin110]

Hi, Mr. Anderson, Thanks for a nice video. Could you explain "Stimulated Emission Depletion". How does depletion work? Do you have a separate video on the "depletion" part?

[@srinityapadma5125]

Thank you so much Sir

[@RSolimov]

fast and to the point, thank you.

[@prajwalbhat3737]

Short and sweet 🤘 really helpful

[@yonaj.503]

Thank you ;) i finally understood what difference between spontaneous emission and stimulated emission

[@isiimsajidintelegence3359]

Thanks for shortcut

[@edrickigianto6772]

Thank you so much for your great explanation, i was so stressed learning about this, and i understand everything now :D

[@charlientumba6673]

Well explained. thank you so much 😄

[@JL-sn1wn]

Incredibly helpful

[@ayushimalviya8846]

thank you soo much it was really very helpful .....

[@santoshkopnar2067]

Thanks sir

[@Amityadav-il2rp]

Thanku so much sir.....love from India ♥️♥️♥️

[@PATELDHARMIKBCI]

it was really helpful and concept clearing about stimulated emission

[@tqaquotes9379]

What is the reason for the electron in higher energy state hit by another photon to go to lower energy state instead of higher state. Why does it not go to a more higher state?

[@aabidmushtaq3243]

As atoms are already in excited state that is they r not in stable state(10^8micro sec)so they Deexcite and it isn't possible for them to go to higher energy level as they are already in unstable position.

[@prashantsinghsisodia6709]

Not sufficient energy

[@snehashishbanerjee2575]

Excellent....

[@sunnypala7098]

Very helpful sr

[@Rousnay]

It is not Atom that moves to energy levels but Electrons.

[@SameerKhan-nd5qb]

Electrons/atoms/ions

[@dozog]

Electrons don't move to energy levels, they move to a more outer electron band. (And that only in the outdated model of the atom) The electron moves to a higher electron band (where they have higher potential energy). as a result of that : The atom is said to be at a higher energy level. What he shows is not the model of the individual electron bands of the atom, but the energy levels of the atom. It is just a representation at another abstraction level.

[@camuruckumlukas726]

No its atoms

[@i.l.zz.a.r1487]

Electron doesn't move .its seem they teleporting .

[@anamitrasarkar5567]

thanks sir for this explanation

[@surbhikakumari7581]

How can atom move? Isn't it that the electrons move from lower to higher energy level?

[@cybrg2644]

Yes

[@musfiqsivan8750]

same problem. How atoms can have energy levels rather than electrons. Found the same atom and energy level stuffs in my textbook but my professor said it was the electrons that moved

[@jainamchheda]

Absolutely it was helpful.... Thanks....!

[@user-kr7do2rq4y]

From to yilan city thank you for the explanation

[@krishnarajthadesar6783]

this is a beautiful video

[@empaulstube6947]

Nice Steve Kerr!

[@aishwaryaagarwal9709]

This video helped me understand this concept very nicely 🙂

[@neochris2]

Why does emission happen? When it "spontaneously" goes back down to the low energy state, what force made it do so, exactly? Why does it not stay stimulated?/how long does it take to decay?

[@adhit528]

why the electron is not absorbing electromagnetic wave? Is stimulated emission is a spontaneous process? how will you explain that phase will same for stimulated emission? (if not spontaneous process)

[@adhisree6993]

Suprb explanation

[@vijgenboom2843]

Thank you ❤️

[@magnitude360withashik7]

Helpful

[@ikraahmed3964]

Yes, yes that was really helpful

[@antrikshsharma9233]

Thanks, very well explained

[@papaji1285]

Yes that was really helpful and I am a boy from India Assam Tinsukia

[@rabbaniasamuelchaudhry7381]

Yes! Incredibly helpful. 😊

[@sanjeevjazzer]

Super helpful

[@muhammadyasoob9150]

great job it was awesome

[@subhamhaldar5841]

It's very helpful. Thank you sir!!

[@yash-xx2pu]

this was a great video !!

[@hadeneh]

very helpful other videos are just making it so complicated TNX

[@TheNikhilmishras]

Great video. But how do partial reflectors work? Thanks a million!

[@saranshbharti7105]

Thanks a lot for this.

[@dnyaneshmahajan3926]

I have a question In a stimulated emission when we provide energy to atom why it does not take place for further excitation?

[@ginasofia8908]

Love this video!! So darn helpful!! Thank you!

[@priyankavasam07]

Explained well.. helpful☺️

[@181adnanasim8]

why electron comes down instead of going up

[@jiyaverma9011]

Because the incident energy is used to make a new photon instead of absorption

[@subhadeeproychowdhury1059]

Very helpful....give more videos like it

[@abdulrahmanmydeenbatcha1907]

Thanks for teaching ♥️ was really helpful

[@madhubhargava5049]

That was really helpful. Thank You.

[@vermadvndr]

Very 👍nicely done

[@dakshbains9538]

thank you love you

[@IndeedTheroyale]

It helped me a lot ...

[@ilyasemredurmus4432]

You are perfect.

[@evaevestone8142]

That was awesome .

[@shivrajsinghnarwariya4032]

बहुत बढ़िया

[@ayeshafarooq1329]

thankyou!! it was very much helpful

[@rohitbhosle6521]

Very helpful thank you

[@davidthemaggot]

i was really looking for an explanation as to why the exited atoms releases a photon when it gets 'hit' by another photon. i don't get it. nice video though, but you didn't explain how a gas laser manages to maintain a population of exited atoms with an electromagnetic field.

[@tom978i]

If the photon allows the atom to make a transition from E1 to E2, it will not make another transition from E2 to E3 since the energy of these excited state are different, if the photon that hit the atom when it was at E2 right before falling back to E1, it will just allow stimulated emission but not making another transition to E3. However if the photon that hit the atom is exactly the energy needed to jump to E3, it will. But its not the case. hope it helps

[@VinayGade]

@@tom978i thanks for clearing my doubt

[@leduck1000]

Why is the whole atom moving up to a higher energy level rather then just the electron?

[@anandh1967]

does this excitation is possible in any atoms ???

[@gangaramgehani4157]

Thanks for the video and afcouse it is helpful.

[@ahmadalhuwaish7504]

LASER stands for Light Amplification by Stimulated Emission of Radiation.

[@ravattar]

Why we get exactly the same photon ? what are the reasons for this assertion? where does it come from? <a href="#" class="seekto" data-time="65">1:05</a>