Problem/Purpose of me asking this question to you people who know more than me:
So I'm doing a science project where I'm collimating a beam of light to a focus point in a light medium (water vapor or fog) and I want to calculate the intensity near it. I can't seem to find an equation that describes this problem. I want to know two things. If you know anything that can be related in solving this problem, it is much appreciated! :)
Issues/Things I need help to figure out!:
(1) If I focus a collimating beam of light with a lens, (say a hand held magnifying glass), into a relatively uniformly dispersed light medium, (water vapor or theatrical fog) Can this focus point be seen in ANY direction, (say like 5 feet away from the focus point)? Doesn't light scatter isotropically in this case? IF NOT, What is the preferred direction of scattering of the light?
(2) If an equation exists (And light scatters isotropically in the light medium used), can this equation say given the parameters, (light frequency used, index of refraction of medium, density of medium, size of collimated beam, lens dimensions used, etc) give the intensity of light in terms of the distance a person is away from the focal point? I am aware of the inverse square law, but in my case, its a bit different, isn't it?
Wouldn't my situation involve some type of directionality? How do you find the best viewpoints from the focal point in which the intensity of the focal point is most profound?
MORE relevant or related questions that need to be addressed:
- Does the particle size matter?, (the particles that make up the light medium)
- How do I determine the correct density of the given medium to produce the most profound effect, (Having the focal point illuminate as brightly as possible)
- How do I determine the right intensity of the initial column of light that is focused?
- Combining the previous two bullets, How do I determine the right combination of the density of light medium and intensity of light used to illuminate the focus point as bright as possible?
What I'm trying to do is to create a "point of light" inside a suspended light medium (Ideally viewable in all directions) and I'm trying to figure a way to figure this out with equations before buying a whole ensemble of things (Fog machine, light source/laser, magnifying glass or multiple lenses, etc) to test it. (If not viewable in all directions, and it has directionality, then I'm just gonna combine multiple systems pointing multiple columns of focused light in different directions to the same point in space to obtain an acceptable looking "point of light" in a medium).