making your own acrylic/plastic lens

[donkeywonkey]

I bought some of lenses recently to make lines or crosses using a laser pointer.

Does anyone know what the process is called that creates this effect? How does one make a pattern to create a desired shape?

If you look closely at the lens it has a wavy shape, but not sure how it corresponds to the resulting laser shape.

I can't post images but if you search for laser line lens or laser cross lens you will see a kind of interference pattern type shape that the lens has on the outside.
For example this one below creates a simple horizontal line.

 

[Cyparagon]

It's just a negative cylinder lens with a short focal length. Two cylinder lenses, one orthogonal to the other, create a cross instead of a line, because half of the beam is passing through each. The "wavy pattern" is because they're fresnel lenses.

 

[andrew6NB]

I bought some of lenses recently to make lines or crosses using a laser pointer.

Does anyone know what the process is called that creates this effect? How does one make a pattern to create a desired shape?

If you look closely at the lens it has a wavy shape, but not sure how it corresponds to the resulting laser shape.

Have you been trying it before?

 

[steve001]

I bought some of lenses recently to make lines or crosses using a laser pointer.

Does anyone know what the process is called that creates this effect? How does one make a pattern to create a desired shape?

If you look closely at the lens it has a wavy shape, but not sure how it corresponds to the resulting laser shape.

I can't post images but if you search for laser line lens or laser cross lens you will see a kind of interference pattern type shape that the lens has on the outside.
For example this one below creates a simple horizontal line.

Extremely thin lines are etched onto the lens surface. If you have a big piggy bank you can purchase the equipment to do that.

 

[Cyparagon]

Extremely thin lines are etched onto the lens surface.

NO. Did you not read the thread? Did you not read my post? Here. HERE's a picture from when I googled line lens.

It's JUST waves in the injection mold, my man.

 

[steve001]

NO. Did you not read the thread? Did you not read my post? Here. HERE's a picture from when I googled line lens.

It's JUST waves in the injection mold, my man.

Golly! bite my head off will ya. A hard carving wax is suitable. A high durometer Tin cure silicone for making a mold. Carving tools. Various grades of fine grit sand paper to produce a polished surface. Perhaps even ultra fine polishing compounds. A water clear casting compound to make the lens. Perhaps a mold release. Perhaps a vacuum pump and vacuum chamber to get rid of bubbles in the casting material. Money to buy all you need plus time to practice.