Re: laser through pinhole

Frogwatch <dbohara@xxxxxxxxxxxxxx> writes:

On Jul 2, 8:06 pm, d...@xxxxxxxxxxxxxx (Don Klipstein) wrote:
In article <1183417971.498468.124...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,

anurag agrawal wrote:
I am trying to assemble a setup to measure the Point Spread Function
of an Optical System. I got a pinhole of 5 microns and need at least 1 mW
output through the pinhole. My boss got me a commercial laser pointer of
about 2mW power and it obviously does not have a good beam quality. Is
there anyway I can get that much power through the pinhole using the
pointer

Use a convex lens to focus down the beam. To get a waist size of 5
microns, the beam of a usual red laser has to converge to and diverge from
the waist at something like 200 milliradians. This means the focal length
of the lens should be not much more than 5 times the diameter of the beam
going into the lens.

- Don Klipstein (d...@xxxxxxxxx)

Use a microscope objective although I doubt you will get 1 mW through
the hole with a commercial laser pointer. You might do better with a
small HeNe laser. Laser pointers have poor beam quality.

Green laser pointers have decent beam quality. This should work, but
precise positioning will be the difficult part.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
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Relevant Pages

  • Re: laser through pinhole
    ... I got a pinhole of 5 microns and need at least 1 mW ... Use a convex lens to focus down the beam. ... the hole with a commercial laser pointer. ...
    (sci.optics)
  • Re: laser through pinhole
    ... I got a pinhole of 5 microns and need at least 1 mW ... Use a convex lens to focus down the beam. ... the hole with a commercial laser pointer. ...
    (sci.optics)
  • Re: laser through pinhole
    ... I got a pinhole of 5 microns and need at least 1 mW ... Use a convex lens to focus down the beam. ... the hole with a commercial laser pointer. ...
    (sci.optics)
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