lens to focus "to square"

[digitos]

Hi, I have bought laser cutter with 5.5W 450nm laser. After testing I have found out that the laser spot is rectangular, which is normal thing for laser diodes, but is there any chance to focus the laser to be square? Any kind of special multifocal lens? It matters when cutting very thin lines on paper.
Thanks for replies

 

[Immo1282]

If you're cutting paper, a 5.5W 450nm laser is huge overkill, and a laser with a tighter spot may be better suited...

The lens you are looking for is called a Cylindrical lens, which has its curve only along one axis instead of two. If you intend to correct the beam this way, there are many threads of people doing this that you'll find in the Optics section of the forum.

Welcome to the forum though - if you're planning on sticking around here, have a read of the sticky threads and post a thread in the welcome section to let people know who you are, what you're into and where youre from

 

[digitos]

Amazing, I will skim through the forum, thank you. I bouhgt this laser to complement (mainly engraving) my bigger 60W co2 cutter. I will do that, I think I could learn a great deal with this forum

Thank you

 

[hakzaw1]

welcome--have you made your 'intro' post in Newcommer/welcome section?--also adding your general location into your proifile info helps us to help you (better). also 'rectangle dot' is mostly common among 450s & a few others to NOT get a round dot..IMO switch to a 405nm (>~100mW) ,, smallest dot and round, cheaper than your 455 and fast burner.. very fast..great for cutting paper.

welcome to LPF hak

 

[paul1598419]

Welcome to the LPF. The cylindrical lenses come in pairs and are AR coated for specific wavelengths. They are actually single axis beam expanders and are rated anywhere from 2X to 6X. For cutting thin lines on paper, you might do better with the 405nm single mode laser diode BDR-209 which can be driven to output 900+ mW in a very thin spot. They are also very inexpensive diodes, but are only 3.8 mm in diameter. So, you will need a TO-38 module and a large enough heat sink to remove all the waste heat from the diode.