Recent content by Aelo

Homework Statement Using the dispersion relation at the Dirac Point calculate the electron density of states for graphene in both the valence and conduction band. Homework Equations ρ = density of states = k2/pi2 The Attempt at a Solution I looked up what Dirac Points...

I solved it, thanks anyway.

Sorry about that... I screenshotted it straight from our PDF textbook. I believe θ = θe.

Homework Statement A uniaxial crystal of indices n0 and ne is cut so that the optic axis is perpendicular to the surface. Show that for light from the outside at an angle of incidence θi, the angle of refraction of the e-ray is Homework Equations The Attempt at a Solution I solved for...

Homework Statement An 80 mm focal length thin lens is used to image an object with a magnification of -1/2. The lens diameter is 25 mm and a stop of diameter 20 mm is located 40 mm in front of the lens. How big is the unvignetted field of view [in terms of object size (in mm) and in terms of...

Thank you very much for your help, I believe I have solved the problem. :)

I think it has to do with sign convention... the formula is usually written 1/f = 1/l' + 1/l, but in my class, it's written 1/f = 1/l' - 1/l. For where it says, what if aperture stop were placed 25 mm to the left, is that just changing the sign of l and that's all? (Also, you've been very...

Bump. :(

The link you posted is very helpful, and I saw that the entrance pupil was formed by the continuation of the extreme ray, but since that continuation doesn't actually exist (as the ray ended up being redirected by the lens), how is the image visible? What rays make it exist? I see how you can...

The position. x2 - x1 is the change in position. Your object starts at one point, and ten seconds later, it's somewhere else. That somewhere else is x2.

Homework Statement A photographer is taking a portrait photo of a person at 6 m distance from his digital camera, which has a sensor pixel size of 10 μm and is equipped with a f = 100 mm thin lens. Image blur is supposed to be limited to the size of one pixel. Which of the following...

Attached is the slide our professor gave us about it. I'm starting with trying it in front of the lens because that's the order in which the questions are asked. In the picture, the pupil image is in some rather ambiguous location between the lens and the aperture and above the aperture, and I...

I'm not sure I really do. I have a drawing from my book that shows the entrance pupil appearing somewhere between the lens and the aperture, and at some height above the aperture, but I have no idea how to determine either of these two values.

Homework Statement An optical system consists of a thin lens in air with f = 100 mm. An aperture stop with a diameter of 20 mm is placed 25 mm to the right of the lens. Calculate the numerical aperture of the system. (Hint: Find the size of the entrance pupil.) What would be the numerical...

Looking at that and this: http://www.regentsprep.org/Regents/math/geometry/GP15/CircleAngles.htm Wouldn't that indicate the upper left corner angle is 90 degrees, so that theta 2 = 180 - 90 - 45?