# Lens that will make the rays parallel to each other

## Main Question or Discussion Point

i need a lens that will make the rays parallel to each other & focal point at infinite.without much loss in the intensity.collimator lens kind of action but not at the cost of intensity.

## Answers and Replies

Related Classical Physics News on Phys.org
K^2
Science Advisor

Very easy. A lens with a focal point at infinity is called a window.

See the fig(attachment).I want to achieve this(shown in fig).

#### Attachments

• 2.6 KB Views: 298

That's just a normal lens, ray lines are independent of the direction of light.

I didn't realise collimators had any loss of intensity, are you using laser light or just a point source?

That's just a normal lens, ray lines are independent of the direction of light.
i am not getting this.

Its not laser light it is the output from a parabolic antenna.with the beam angle of about 10-15degree.

I 'm not sure i fully understood your question but you try using two lenses.
The 1st (focal length f1) to focus the light at a point and the 2nd (focal length f2) to get a parallel ray output.
The 2nd lens must be placed with its focal length at the focus point of the 1st i.e., at a distance f1+f2 from the 1st.

What frequency are we talking about?

microwave.have heard somewhere all the emwaves have the same properties as light.parabolic antenna is an example of that,as reflection of radio-microwaves is observed here just like light.