Optics question involving light waves

In summary, the problem involves a 100W light bubble with 2% efficiency converting to visible light, with only 10% passing through a filter. The electrical field of the light in the filter is given by E(r) = Eo(r)[(∏*10^15) (t - r/(.65c))]. The frequency and wavelength of the light, as well as the type of color filter and index of refraction, are to be calculated. The intensity of light detected and number of photons detected per second are also to be determined. The problem also involves determining if the filter has normal or abnormal dispersion in the filtering wavelength range.
  • #1
koolbklyn
1
0
I tried to solve this question. NO idea if I'm even on the right track.


Homework Statement



Suppose irradiation of a 100W light bubble (very small - be assumed as point source)
is homogeneous in all directions. Because of low efficiency, only 2% of the electrical
energy will be converted to light energy in the visible range, among which only 10%
passes through the filter. The filter is located at 1m away from the bubble and followed
immediately by a large 1mm-squared photo detector.
Assume that the electrical field of light traveling in the filter is given by:

E(r) = Eo(r)[(∏*10^15) (t - r/(.65c))]

1. Write the mathematical equation of E(r) (ignore the surface loss of the filter).
2. Calculate the frequency of light?
3. Calculate the wavelength of light?
4. What kind of color filter is used?
5. What is the index of refraction of the filter?
6. What is the intensity of light detected (assume quantum efficiency is 0.65)?
7. How many photons will be detected per second?
8. Is the filter likely to have a normal or abnormal dispersion in the filtering wavelength range?

Homework Equations



[itex]\upsilon[/itex] = frequency
[itex]\lambda[/itex] = wavelength
c= speed of light
[itex]\epsilon[/itex]o = vacuum permittivity


The Attempt at a Solution




1. E(r) = Eo(r)[ωt - r/c]
2. E=hc/[itex]\lambda[/itex]
3. [itex]\lambda[/itex][itex]\upsilon[/itex] = c use [itex]\lambda[/itex] from Q2. to solve for [itex]\upsilon[/itex]
4. colour depends on the wavelength
5. 0.65/c = n filter / n of medium
make medium air . Therefore n of medium= 1 and nfilter = 0.65
6. I = [(.65cn[itex]\epsilon[/itex]o)/2] * E^2
plug in and solve for I
7. NO idea
8. NO idea.
 
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  • #2
by any chance, is this for biosensors?

I'm trying to figure out the problem myself. I got something similar for 1.
I'm working on 2. Do you know if we're supposed to figure this out for filtered light or unfiltered?
 

1. What is the difference between reflection and refraction?

Reflection is the bouncing back of light waves when they hit a smooth surface, whereas refraction is the bending of light waves as they pass through a different medium.

2. How does the color of an object affect the way it reflects and absorbs light?

The color of an object is determined by the wavelengths of light that it reflects. Objects that appear red reflect red wavelengths of light and absorb all other colors.

3. What is the relationship between the angle of incidence and the angle of reflection?

The angle of incidence and the angle of reflection are equal when light is reflected off a smooth surface. This is known as the law of reflection.

4. How does the thickness of a lens affect its ability to refract light?

The thicker the lens, the more it will refract light. This is because the thicker lens will cause the light waves to bend more as they pass through.

5. What is the difference between a convex and concave lens?

A convex lens is thicker in the middle and causes light waves to converge, while a concave lens is thinner in the middle and causes light waves to diverge.

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