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ehummel
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Hi all, can a laser light be magnified by means of a magnifying glass?
ehummel said:Hi, i am referring to making the beam brighter by focusing the beam to a smaller beam like when one focuses sunlight thru a magnifying glass.
mgb_phys said:Yes you can - but a laser beam is generally already pretty small and you would need fairly good optics for the focussing down to win over optical errors scattering light out of the beam.
A microscope objective would work, a dollar store magnifying glass wouldn't.
Nope, you can squeeze the beam down to make the point brighter but at the other side of the minimum point the beam spreads out - it doesn't restore any of the light lost by the mirror bounces.ehummel said:I don't know much about optics so I may be totally off base with this thought. I was thinking that if I introduce a magnifying glass at the point where the visual brightness of the beam drops off, i could get a few more bounces out of it.
mgb_phys said:Nope, you can squeeze the beam down to make the point brighter but at the other side of the minimum point the beam spreads out - it doesn't restore any of the light lost by the mirror bounces.
The mirror's are losing light because of reflection losses and because they are not perfectly flat and so some light is being scattered out of the beam.
ps. Be careful a laser that can ignite matches can easily damage your eyesight with even an accidental reflection from a shiny bit of metal like a watch strap or a dropped part.
Archimedes death ray: http://en.wikipedia.org/wiki/Archimedes#The_Archimedes_Heat_Ray_.E2.80.93_myth_or_reality.3Fehummel said:BTW: what is Archimedes' mirror trick? Sounds interesting...
Maybe we're just talking past each other here. Are you saying that you can't make a "bright" spot by reflecting some sunlight with a mirror, then make it brighter and hotter by adding more mirrors? [edit]...or a magnifying glass or large telescope, for that matter (except that the mirrors in the solar tower are flat).Andy Resnick said:No. Radiometric brightness (sometimes also called the etendue) is a conserved quantity.
http://en.wikipedia.org/wiki/Etendue
http://en.wikipedia.org/wiki/Radiance
Archimedes' death ray is impossible in principle due to thermodynamic considerations, which I have discussed in previous threads.
Yes, a laser light can be magnified with a magnifying glass. This is because a magnifying glass is designed to bend and focus light rays, including those from a laser.
A magnifying glass is made up of a convex lens, which is thicker in the middle and thinner at the edges. When a laser beam passes through this lens, it is refracted (bent) and focused, making the laser light appear larger and brighter.
The maximum magnification that can be achieved with a magnifying glass depends on the strength and quality of the lens. Generally, a magnifying glass can magnify an object up to 10 times its size.
Yes, any type of magnifying glass with a convex lens can be used to magnify a laser light. However, it is important to note that the quality of the lens will affect the clarity and brightness of the magnified laser light.
Yes, it is important to take safety precautions when using a magnifying glass to magnify a laser light. Direct exposure to a concentrated laser beam can be harmful to the eyes and skin. Therefore, it is recommended to wear protective eyewear and handle the magnifying glass carefully.