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How to Make a Collimator From Two Lenses

A collimator is a device designed to align a beam of particles or waves in a specific direction. It also narrows the spatial cross section of a wave. Collimators are, therefore used to improve the resolution of optical devices such as telescopes. Laser collimators are also used in industrial and hospital radiographs and X-ray machines. While collimators used in such devices require complex designs, you can design a simple collimator at home from materials available at your local hardware store.

Things You'll Need

Laser pointer, 1 1/4-inch diameter
Concave lens, 1 1/4-inch diameter
Convex lens, 1-inch diameter
PVC pipe, 4 inches long and 1-inch diameter
PVC pipe, 4 inches long and 1 1/4-inch diameter
Epoxy glue
Toothpicks
Adhesion tape

Instructions

- 1
  Place your concave lens in front of the laser pointer on a flat surface so their outer rims almost touch each other. Position the convex lens behind the concave lens and move it back and forth to identify the distance between the two lenses that gives you maximum divergence. The distance for maximum divergence (the point at which the light spreads out as much as possible) will vary, depending on the intensity of the radiation from your laser pointer. You may use this measurement to adjust the distance between the collimator's outer and inner tubes.
- 2
  Use a toothpick to apply the epoxy glue to one end of the larger PVC pipe and stick the concave lens to it. This will be the collimator's outer tube.
- 3
  Attach the convex lens to one end of the smaller PVC tube with the help of the epoxy glue and the toothpicks. This is the collimator's inner tube. Let the glue dry. The drying period for the glue may vary. Read the instructions on your glue packet to determine the drying period.
- 4
  Slide the inner tube carefully into the outer tube with the convex lens facing the inside of the outer tube. Use the adhesion tape to attach the laser pointer to the other side of the concave lens. The inner tube moves within the outer tube. Adjusting its position per the measurements from Step 1 can help achieve maximum divergence.

Astronomy