Recent content by dziech

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    Understanding the Negative Sign in Laser Linewidth Calculation

    That clicked! :D I can finally sleep peacefully ;) Thanks!
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    Understanding the Negative Sign in Laser Linewidth Calculation

    Am I just thinking of this the wrong way? I mean, Δν is a linewidth in frequency. Say it's 60GHz, the Δλ should be like 0.2nm at 1um, but it would be -0.2nm wouldn't it? Or should I think of it as Δν change in linewidth? But that doesn't make obvious sense to me. It's one of the questions I...
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    Understanding the Negative Sign in Laser Linewidth Calculation

    Hi guys, It's one of the questions I'm asking myself needlessly but I really wonder about this ;) Say I have a laser at a wavelength λ. I can calculate the frequency by ν=c/λ. Then the linewidth Δν=cΔλ/λ2 that can be found through differentiation of two sides of the equation. The question is...
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    What is the error analysis for a function of Newton's cooling law?

    Yes, sorry, sometimes I forget to keep things straight forward : ) Ok, great - this is exactly where I got stuck: the derivative with respect to ##\tau## will in the end include time wouldn't it ? So : ## f = T_{ambient} + (T(0)-T_{ambient})e^{-kt}## Now I keep the t as a constant (if I...
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    What is the error analysis for a function of Newton's cooling law?

    Ok, maybe more context will help : ) I have samples of a solid cooling down. I do data fitting with Levenberg Marquardt algorithm to find ##\tau## - time constant of the exponential function. Now I want to calculate the uncertainty of the time constant ##\tau##. Let's put it simple - what are...
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    What is the error analysis for a function of Newton's cooling law?

    I asked my question in a wrong way. The uncertainty i want to measure is the one if the time constant. Then it's a function of tine and temperature. The question remains, is the t value that stays in derivative a value over i made my calculations? It makes sense if i take the uncertainty of the...
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    What is the error analysis for a function of Newton's cooling law?

    Hi guys, I have a silly question, but I seem to be confused about it. Let's say I have a function of Newton's cooling law. I measured the exponential drop of the temperature of some system and now I want to make an error analysis. Do I treat this function as a two variable function of tau (time...
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    Can you make plasma with UV Rays?

    Hey plasma1, Just a quick thoughts about that plasma project. Firstly, I think that the plasma is not created by UV light, the UV is created due to the chemical reactions on the sun - nuclear fusion. Correct me if I'm wrong ; ) Secondly, scientists are already working on creating the...
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    Phase retrieval problem for laser profile

    Thank you all for replies. I've been traveling a bit, so sorry for a long delay. Anyway, I am now getting through that thick paper you suggested... really hard stuff in there for me. But I am trying :) Also, if I understand correctly, Gerchberg Saxton should work if I also involve some...
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    Phase retrieval problem for laser profile

    Good morning, Before all, I also posted a question to maths forum, but I am convienced that this is the forum I was more like looking for. Firstly, hello to this forum, secondly I want to apologize if this is not a place I would like to post a question like that, maybe in another thread ?; )...
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