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@valentinodrachuk5692 Ай бұрын
I really like his way of teaching. Don't understand way so many negative comments.
@JohnVKaravitis Ай бұрын
FIRST!
@JohnVKaravitis Ай бұрын
13:12 Immerse the box in mineral oil. DON'T rely on air cooling!
@JohnVKaravitis Ай бұрын
42:35 His formula gives the spectral energy density, not the spectral radiance.
@hamed.jafarishad 2 ай бұрын
1:51:40, Rayleigh scattering is stronger at lower wavelengths (higher energies) and it is proportional to the reciprocal of wavelength to the power of 4.
@ribe-gt4rb 3 ай бұрын
All great content as the previous videos. I finally really understand how lasers works. Just an unimportant point about the color green: The reason it seems there is a huge amount of green component energy in the sun light is that it is reflected by plants (because they don't need it).
@ribe-gt4rb 3 ай бұрын
So, we can see that trees are not sensitive to green to the extent he says.
@Lynaelary 3 ай бұрын
Great introduction....
@chevestong 4 ай бұрын
19:05-20:58: - Differential solid angle explanation for spontaneous emission component of dI/dz
@liadivgi8160 4 ай бұрын
is there a chance to get the code presented?
@chevestong 4 ай бұрын
48:00 - 51:02 -- The very important concept that with only 2 energy levels, population inversion is impossible. 48:34 - End - Analysis of Verdeyen's equation (7.4.6); the pump-less rate equation for upper state 2.
@chevestong 4 ай бұрын
These last 3 lectures (lectures 16-18) really are the core/heart of laser operation, for those who are watching through this series. Dr. Pollock does an amazing job providing the intuition behind the theory in these 3 lectures. Thank you Dr. Jena, for posting this!
@manbeast1586 4 ай бұрын
Excellent work, thank you
@memsuniverse 5 ай бұрын
Hidden gem course explanation: I am new to the laser world, and I am thoroughly enjoying every single second. Thank you for sharing it
@nivesh3555 6 ай бұрын
I also get the second derivative wrt z in the 3rd equation(equation for psi). Could anyone explain how the second derivative wrt z was cancelled from equations 2 to 3?
@peterazure246 7 ай бұрын
Clear and Concise.
@Ravikumar-wy2dj 7 ай бұрын
43:27
@rajiblochanghadei_1105 8 ай бұрын
Is Debdeep Sir from Odisha State ( of India ) ???
@IfteKhairulAlamBhuiyan 8 ай бұрын
Can you upload better resolution?
@polarkerr 9 ай бұрын
Great work Professor
@ruchisingh2177 9 ай бұрын
Brilliant🎉🎉🎉
@inayathussain9236 10 ай бұрын
I think there is a little mistake at 1:06:50 . Vb + abs(Vo) should be from the conduction band on p-side to the conduction band on n-side.( or equivalently between the valence bands on the two sides).
@user-hn1nb6pk1u Жыл бұрын
Where is voice ?
@Sai-vr3mk Жыл бұрын
Great lecture! Definitely one of the best introductions to Electronic Theory of Solids out there. Thank you Dr. Debdeep Jena!
@ismaillahmini6604 Жыл бұрын
Thank you so much for this amazing lecture What i didn't get is the graph E(k). n is always positive but why we have such as graph. Why we have the negative part of the graph although we dont have a negative k ?? This is my question
@fingertipsandcompany2195 Жыл бұрын
Very good, thanks!
@sebastiankalos7656 Жыл бұрын
These lectures are helping me greatly during my first year as phd student, thanks so much!
@frankdimeglio8216 Жыл бұрын
WHAT DIMENSIONS WOULD INVOLVE THE MAXIMUM AREA OF SPACE ?: Visible AND VISIBLE SPACE in fundamental equilibrium AND BALANCE is CLEARLY the answer. TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. E=mc2 is taken directly from F=ma. This CLEARLY answers the question: What dimensions provide the maximum area of SPACE (ON BALANCE)? Since gravity cannot be shielded (or blocked), it has to be fundamentally BALANCED with (or equivalent to) what is ELECTROMAGNETISM/energy regarding what is invisible AND VISIBLE SPACE in BALANCE. Great. The dimensions of SPACE are CLEARLY, necessarily, AND fundamentally balanced. That is obvious. TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. BALANCED inertia/INERTIAL RESISTANCE is fundamental (ON BALANCE). E=mc2 is taken directly from F=ma. Consider TIME (AND time dilation) ON BALANCE. Consider what is a TWO dimensional surface OR SPACE ON BALANCE. (Fully consider what is THE EYE ON BALANCE.) ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). c squared CLEARLY represents a dimension of SPACE ON BALANCE. The stars AND PLANETS are POINTS in the night sky ON BALANCE, AND consider what is the speed of light (c) ON BALANCE. This CLEARLY explains the fourth dimension ON BALANCE. By Frank DiMeglio WHY c SQUARED CLEARLY REPRESENTS A DIMENSION OF SPACE ON BALANCE, THEREBY PROVING E=MC2 AND THE FOURTH DIMENSION: c squared CLEARLY represents a dimension of SPACE ON BALANCE. The stars AND PLANETS are POINTS in the night sky ON BALANCE, AND consider what is the speed of light (c) ON BALANCE. E=mc2 is DIRECTLY taken from F=ma. TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. You have to understand TIME AND time dilation ON/IN BALANCE. SPACE cannot be possible/potential AND actual ON/IN BALANCE unless it is: Invisible AND visible SPACE in fundamental equilibrium AND BALANCE. What is an inherently two dimensional surface OR SPACE ON BALANCE. (Consider what is THE EYE ON BALANCE). GREAT !!! Consider, for example, Einstein rings. Do notice what is the ASSOCIATED black “space” AND DOME regarding WHAT IS the eye. By Frank DiMeglio Define “mass”. Exactly what is “mass”? You cannot. BALANCED inertia/INERTIAL RESISTANCE is fundamental (ON BALANCE). Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE consistent with F=ma AND E=mc2. Accordingly, ON BALANCE, the rotation of WHAT IS THE MOON matches it's revolution. INDEED, “mass”/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent with/as what is BALANCED electromagnetic/gravitational force/energy. E=mc2 is taken directly from F=ma. SO, objects AND MEN may fall at the SAME RATE (neglecting air resistance, of course); AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). Great. I have revolutionized physics. Notice what is the TRANSLUCENT blue sky ON BALANCE. Consider what is BALANCED BODILY/VISUAL EXPERIENCE. E=mc2 is taken directly from F=ma. Accordingly, ON BALANCE, the rotation of WHAT IS THE MOON matches it's revolution. Again, TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. GREAT !!!! Finally, consider what is the orange (AND setting) Sun ON BALANCE; AND consider what is the fully illuminated (AND setting/WHITE) Moon ON BALANCE (in what constitutes DIRECT COMPARISON). Notice that lava is orange, AND it is even blood red. Magnificent. Said Moon and said Sun are CLEARLY the SAME SIZE as what is THE EYE ON BALANCE. Notice that they form or manifest at what is EYE LEVEL/body height. The curvature or shape of said Moon does match that of THE EARTH/ground (given a clear horizon, of course). The average ocean tide is about six feet, AND the tide in the middle of the ocean is about two feet. Excellent. ON BALANCE, said Moon is CLEARLY proven to be (and it is predicted to be) about one quarter the size of what is the Earth. E=mc2 is taken directly from F=ma. ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). By Frank DiMeglio
@JoelRTLCosta Жыл бұрын
Amazing professor. I wish I had the chance to be his student when I did this exact same subject!
@maxd8132 Жыл бұрын
@0:46 when he writes the electric field, he has a w0/w0 term.. Is it a mistake or am I totally not following ?
@chevestong 5 ай бұрын
The full equation is: E(x, y, z) = [w₀/w(z)] * exp[ - (r/w)² ] * exp[ -j (kz - atan(z/z₀)) ] * exp[ -j (k r² / 2R(z)) ]. But, w(z) = w₀ * sqrt[ 1 + (z/z₀)² ], so you get what Dr. Pollock writes out at 0:46.
@divyanshuvadehra3779 Жыл бұрын
You are an inspiration, professor ☺️
@odvutmanush3234 Жыл бұрын
Amazing lectures. Will it be possible to get the solutions of the problems , Please?
@2aa22a Жыл бұрын
LOSER is so appropriate! This dude does a very good job in explanation.
@leif1075 Жыл бұрын
Except I don't think he explained well when the electron is in the excited state and the second photon comes in, how do we know for sure the second photon is enough to knock the first photon out of the electron..it could conceivably just nudge or move the lectionary without causing the electron to emit the photon..it might depend on the amount of energy..and why can't an electron absorb a second photon and jjst move to the second excited state? Does it simply not "fit" in the photon? Or is not stable enough to accept it?
@prachiargulewar4416 Жыл бұрын
@@leif1075 if electron had to move to second excited state photon should have that much energy to support second excitation but i think the incoming photon has the energy equal to absorbed one , though i am also not how does second photon interact with excited electron to produce two photons
@salvatorecipressa4753 Жыл бұрын
At minute 18:15. I understand why the cavity can resonate theoretically different frequencies, but if the frequency of the laser only depends on the energy levels of the gain medium, where the other frequencies come from? Underneath the gain bell curve shouldn’t just one frequency be real and the other ones just theoretical?
@ummeraltaf2085 Жыл бұрын
Very nice. This is the way people should teach. Really impressive.what a understanding.
@ummeraltaf2085 Жыл бұрын
Very nice. This guy has best teaching experience and best understanding.very impresive.
@surig9018 Жыл бұрын
Wow 38:31, Great course Prof.D.jena. Thank you for sharing in KZbin.
@user-kd4sd5tt5c 2 жыл бұрын
😍♥️GOOD
@TopicsInControlSystems 2 жыл бұрын
Great presentation, thanks!!
@brendawilliams8062 2 жыл бұрын
Thankyou.
@brendawilliams8062 2 жыл бұрын
Thankyou. A very nice lecture. Excellent.
@brendawilliams8062 2 жыл бұрын
It seems the Alice and Bob is alive and well.
@brendawilliams8062 2 жыл бұрын
Thankyou
@brendawilliams8062 2 жыл бұрын
I thought 101025
@brendawilliams8062 2 жыл бұрын
Thankyou
@brendawilliams8062 2 жыл бұрын
Thankyou
@jaysethi4423 2 жыл бұрын
Real good lecture Professor Pollock! I was able to follow 1st second to the last
@felipehugobragabittar2806 2 жыл бұрын
well.. thats my first approach with abcd matrix... WHY prism isn't treated as index medium change? just like the matrix air | glass interface?!
@MrBogdanel1285 Жыл бұрын
That isn't how you treat the prism. But, indeed, it isn't an ABCD matrix, it is a 4x4 matrix. It is a spatial-temporal coupling. (Not in ray tracing. In real laser beams - Gaussian optics)
@felipehugobragabittar2806 2 жыл бұрын
yeah. that was a heavy class. if you are not with maxwell in mind, with this equations fresh. you are going to lose your time here. Balanis book is a must before take this class
@brendawilliams8062 2 жыл бұрын
I have no problem following some of his ideas and I am not top of this material.
@user-si1zn3ir7x 2 жыл бұрын
Thankyou for the lecture! However,perturbation you did seems like a lcao method
@younesrabhi5298 2 жыл бұрын
the best professor in the hole world