Recent content by test1234

Thanks maajdl for the quick reply. Hmm... if ∂T/∂t=1, then the first order derivative of ∂A/∂T will still exist... Based on my understanding, z is the direction of propagation of the pulse. So the pulse travels with a group velocity \nu_g.

Hi there, I'm having some difficulty in understanding how the change of variables by considering a retarded time frame can be obtained for this particular eqn I have. Say I have this original equation, \frac{\partial A}{\partial z} + \beta_1 \frac{\partial A}{\partial t}+ \frac{i...

Thanks SteamKing! I suppose my second intepretation should be the correct one instead.

Hi there, I'm kind of rusty on some stuff, so hope someone can help enlighten me. I have an expression E(r,w-w0)=F(x,y) A(z,w-w0) \exp[i\beta_0 z] I need to substitute this into the Helmholtz equation and solve using separation of variables. However, I'm getting problems simplifying it to...

Thanks UltrafastPED! =) Just a quick clarification, for the Gaussian matrix method, is it right to say that I would need to start from the leftmost collimated output and propagate it through the two focusing lenses (4f setup) before finally reaching the focusing lens at the other end?

Hi there, I've been trying to solve this problem regarding relay imaging so that I can modify my experimental setup accordingly. Please refer to the attached jpg file for the lens setup. I am trying to image the object (the purple block in the attached jpg file) at a specific imaging plane...

Thanks Ackbeet! Your dissertation is indeed very helpful! Now I have a better understanding of what's happening. Thanks a lot! =)

Thanks for your insightful summary. Yes, I understand that mode-locking usually takes up only a chapter or a few chapters at best in most textbooks, but nonetheless, I think I could benefit from them, hope you can drop me some references. =) In addition, would you happen to know how to...

Hi silversuf, 20dB is a decrease in intensity of 100 times. Therefore, the intensity level of the observed sound is 1/100 times that of the original sound. 20(dB)=-10~log_{10} \frac{I_{new}}{I_{original}} \frac{I_{new}}{I_{original}}=10^{-2} I_{new}=10^{-2} I_{original}=10^{-2} \times 200...

Thanks Marioeden! Hmm...forgive me for the next qns, how do you find one which works? Is there a general form depending on the type of differential eqn you have? So after guessing the certain form that A should be, we can just substitute A into L_t+LA-AL and if this equates to 0, then the...

Hi there, I'm working on fiber lasers and I'm interested in getting up to speed with the topic of mode-locked fiber lasers. However, I can't seem to find resources suitable for me at this current stage, hope that you guys can help recommend a suitable review paper, book or anything that's...

Hi there, I'm learning about solitons and chanced upon this pdf talking about the inverse scattering method. However, I'm stuck trying to derive the coefficients using the LAX method (pg 5 of the attached pdf or from http://arxiv.org/pdf/0905.4746.pdf). Hope that someone can help shed some light...