Engraving laser machine with a lens

[sml2010]

Hi
I have a laser beam(engraving laser machine) and then use a lens for focus the beam but my lens has a crack on the center of lens and when i use my laser in high power the beam diameter will bigger and burning area zone is bigger so:
1- Does the crack doesn't let the maximum focus?in law or high power?
2-1- I if i use two lenses with a exact distance, does the final beam diameter will be smaller than one lens?
2-2- Does the focus distance will be double?
2-3- Does the power will be double?
2-4- does a real distance(focus distance) between two lenses is necessary? if i put the second lens in focus distance of first lens, it will broken or not?

I am wait for your help.

Thank you

 

[CWatters]

The crack will probably be full of air which has a different refractive index to the glass the lens is made of. So it's possible to get reflections and scattering off the surface of the crack.

 

[mfb]

1- Does the crack doesn't let the maximum focus?in law or high power?

The crack is always a deviation from the ideal shape. Sure.

2-1- I if i use two lenses with a exact distance, does the final beam diameter will be smaller than one lens?

Not necessarily, but it is possible.

2-2- Does the focus distance will be double?

Depends on the lenses (in general: no).

2-3- Does the power will be double?

Energy conservation? ...

2-4- does a real distance(focus distance) between two lenses is necessary? if i put the second lens in focus distance of first lens, it will broken or not?

If the laser intensity is sufficient, you can even heat lenses (which are designed to let most light through it), sure.

 

[Andy Resnick]

Hi
I have a laser beam(engraving laser machine) and then use a lens for focus the beam but my lens has a crack on the center of lens <snip>
I am wait for your help.

You should replace the lens.

 

[sardar]

for your question. I can provide some insights and answers to your questions regarding the use of a lens in an engraving laser machine.

1. The crack on the center of the lens can definitely affect the maximum focus of the laser beam. This is because the crack will cause the laser beam to diffract and scatter, resulting in a larger beam diameter and less focused beam. This will be more pronounced in higher power settings as the laser beam will have more energy and will be more likely to diffract off the crack.

2.1. Using two lenses with an exact distance between them can result in a smaller beam diameter compared to using just one lens. This is because the first lens will focus the beam and the second lens will further refine and concentrate the beam, resulting in a smaller diameter. However, this will also depend on the quality and condition of the lenses.

2.2. The focus distance will not necessarily be double if you use two lenses. It will depend on the distance between the two lenses and the focal lengths of each lens. It is important to calculate and adjust the distance between the lenses for optimal focus.

2.3. The power will not necessarily be double when using two lenses. It will depend on the efficiency of the lenses in focusing the laser beam. In some cases, using two lenses may actually result in a decrease in power due to loss of energy through multiple lenses.

2.4. A real distance between two lenses is necessary for proper focusing and to avoid damage to the lenses. If the second lens is placed at the focus distance of the first lens, it may result in damage to the lenses due to the concentrated laser beam.

I hope this helps to answer your questions. It is important to always use high-quality and undamaged lenses for optimal performance and safety when using an engraving laser machine. If you have further questions or concerns, I suggest consulting with a professional or the manufacturer of your laser machine.