2,347 reputation
1124
bio website nl.linkedin.com/in/…
location Canada
age 32
visits member for 3 years, 5 months
seen yesterday

Mar
13
comment Getting nonphysical results when solving for the index of refraction of a slab?
I was giving you long conjectures in the comments and finally I decided to stop conjecturing and make a real answer out of it ;-)
Mar
12
comment Getting nonphysical results when solving for the index of refraction of a slab?
What @SteveB says: It would not be at all surprising for this kind of data to be systematically shifted up or down a bit compared to reality. This has happened to me many times.
Mar
11
comment Getting nonphysical results when solving for the index of refraction of a slab?
How did you normalize your R and T measurements? Out of curiosity, what happens with the computed n if you add an offset of 0.2 to either?
Mar
5
comment Optics - Faraday Rotator using waveplates
You can't. Waveplates are reversible, a Faraday rotator is not.
Dec
13
comment Why is the decibel scale logarithmic?
That's incorrect, the decibel scale is logarithmic: +10 dB gives 10x the sound pressure (and +3 dB gives about 2x, as you say) so +20 dB (100-80) gives 100x. In other words, $2^{(100-80)/3} \approx 100$.
Dec
12
comment Exciting Surface Plasmon-Polaritons with Grating Coupling
Take $\theta_o = \pi/2$, so the grating equation becomes $d(\sin\theta+1)=\nu\lambda$. Then $k=2\pi/\lambda$, and $g=2\pi/d$. The difference between $k$ and $\beta$ is because $\lambda$ is different for the surface plasmon.
Sep
28
comment Law of reversibility of light and total internal reflection
Time-reversal symmetry still holds over a boundary between media (though not if the media are lossy.) In the general case you would get four beams, yes, but if you reverse the reflected and transmitted beams and they come together again with the appropriate relative phase difference that they had in the forward case, then they will destructively interfere in the pathway of the fourth beam, and all the energy ends up in the original beam.
Aug
1
comment Vibrations after polarization of light
They don't oscillate in a single plane. The electric field oscillates in a plane, and the magnetic field oscillates in a plane perpendicular to the electric field. The plane of polarized light refers to the plane in which the electric field oscillates, not the magnetic field.
Jul
27
comment Vibrations after polarization of light
In a plane wave, the electric and magnetic fields always both oscillate, and they always both oscillate perpendicular to each other.
Jul
13
comment Transmission vs reflection grating
I think no-one's answered this yet because it really depends on what you're trying to do with it. Can you make your question more specific?
May
12
comment What's the physical significance of using fourier transform for diffraction?
I wrote an answer about that here a while ago...
Feb
28
comment Rubber band stretched produces heat and when released absorbs heat.. Why?
@Nathaniel My final term freshman year project in university was to build one of those. It's been a long time so I don't remember the details, and I think I lost the project report :-P We insulated the water in a styrofoam container to keep the environment from warming it up too much, and it got quite cold to the touch. We weren't able to get it anywhere near freezing though.
Feb
23
comment Optical trapping problem
You've got the wrong idea about optical trapping. Or perhaps you're referring to something I've never heard of? Can you elaborate?
Jan
27
comment Spectral luminous efficiency as a function of wavelength
Do you have a reliable source for that?
Jan
4
comment Why doesn't my pinhole camera work?
+1 for doing your own experiment though!
Nov
19
comment Photon energy - momentum in matter
actually, three: 1) $p=\hbar k$ is only valid for a photon in a plane wave mode, which people usually gloss over; 2) saying that phase matching is due to conservation of momentum is not accurate, despite it being popular to say in nonlinear optics; 3) of course you are right that the photon is traveling mostly in vacuum and so has $p=h\nu/c$; but that expression is useless at the scale of macroscopic dielectric media.
Nov
19
comment Photon energy - momentum in matter
I've thought and discussed about it some more and come to two insights:
Nov
19
comment Photon energy - momentum in matter
Indeed, the Abraham-Minkowski controversy is divided between whether the momentum of a single photon is larger or smaller in a dielectric, but it certainly doesn't stay the same!
Nov
19
comment Photon energy - momentum in matter
@MarkMitchison I'm aware that photons appearing to travel slower in water is purely due to averaging. However, the momentum of a single photon is h-bar times the wave vector, and the wave vector's magnitude is larger in a denser medium with a slower speed of light. This is how phase matching works in nonlinear optics - conservation of momentum. Also, surface plasmon resonance excitation mechanisms (such as the Kretschmann configuration) are explained by different photon momenta in different materials.
Nov
2
comment Are circular polarizations a basis for any light polarization?
In or out of the plane of reflection when reflecting off a surface: en.wikipedia.org/wiki/…