# How to widen a laser beam?

## Homework Statement

I need to be able to widen the beam of a laser for an experiment I am doing. I want to increase the area the beam takes up while preserving the total amount of light passing through a plane. I provided a diagram of a way I think I can do this, but I would appreciate any other insight on how else I could do this. Though most lasers output a circular beam of light, a solution that enlarges the area, but in a way that makes the resultant beam shape non-circular is also okay (but not preferred). Assume infinite resources available.

I'd like to know about any optical devices or optics component setups that will achieve this.

## Homework Equations

I'm asking for a more conceptual answer more on how to do this rather than any specific numerical solutions to an exact case. However, this may help:

1/d_i + 1/d_o = 1/f, where

d_i = image distance
d_o = object distance
f = focal length

## The Attempt at a Solution

The diagram I attached shows how I think a bi-concave lens followed by a bi-convex lens should do the trick, though my concern is that it will be tricky to put the laser directly through the center.

Thanks PF!

#### Attachments

• lenses.jpg
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