Recent content by metatrons

These questions are really interesting; although seem simple, some are close to the very nature of the electromagnetic theory, which is very hard to explain. My answers are as follows: How does an electric charge produce an electric field? The electric 'field', is a virtue measure of the...

Usually, this 'anamalous dispersion' is required when acquiring BOTH negative permittivity and permeability, or single negative permeability (as natural materials have no magnetic response at visible wavelength). The negative permittivity is actually very common in natural metals at optical...

tech99： For a good metal, at low frequency （lower than plasmon frequency）, its permittivity (real part) is negative, and at high frequency (higher than plasmon frequency) the permittivity (real part) becomes positive. It is very important to understand the permittivity as the 'overall material...

Hi BlackHole213: You have asked a very 'big' question, and a sound explanation may require a very good fundamentals of the material and electromagnetic-dynamic science. I will try to provide my answer while avoiding the very complicated mathematics and theoretical terminlogies here. But please...

This question is very ambiguous, as diffraction is a very complicated process, normally you need to specify your condition. But in general, the diffracted beam from a plane-wave is no longer a plane-wave. You can consider the diffraction as the interference （superpositions） from a...

Hi mgkii: A very, very important point to understand the Field Energy of a propagation EM wave is that, this energy is a kind of 'potential energy'. The actual power of a EM-wave on a given time is not only dependent on the exact field amplitude at this time, but also dependent on 'the...

Other than that I did not find anything wrong in both derivation. I would also like to see if there are a sound explanation about it.

I believe the first answer is correct, with very solid derivation. For your second approach, I am not sure about your Equation-3. If I understand correctly, it requires the assumption of a uniform field distribution. However, here the field distribution in the sphere should be non-uniform...

Basically 2#, 7#,8#,10# are very good physics explanation to your question. For this matter, I can try to give a simple summarized answer for your question: The diffraction is highly dependent on wavelength. For a good observable diffraction from an opaque object (or a transparent hole), the...

Thanks a lot! I will try to find a way to read this book and study the details of it. Here, I assume a perfect angle reading and linear polarizer, and the only source for imperfection is from the imperfect quarter wave plate. But still I am eager to learn the standard method. Thanks!

Thanks a lot for your hint! If I understand you correctly, the output beam can be approximated as a elliptical polarized beam, and the sinusoidal function is used to fit the short and long axis of the ellipse. Here, I suppose the sinusoidal function should describe the field amplitude rather...

Thanks for your reply! Here, I assume our beam (after the QWP) is fully-polarized-it either contains circular polarization component, or linear polarization. However, the problem is, say, I have the spectra set (transmissions in different angles of 2nd linear polarizer), how can I calculate...

Dear All: I have recently encountered a small question regarding the determination of the degree of circular polarization of light. In an optical experiment, we are trying to create a circular polarized light beam by passing a HeNe-laser through a linear polarizer and a quarter wave plate (in...

The wave-vector is a 'vector' which contains both amplitude and direction. The amplitude is equals to '2pi/lambda' (lambda is the effective wavelength in the specific medium); Its direction is perpendicular to the 'wavefront'-a virtue surface of equal phase. For an ideal plane-wave, the...