You probably refer to FAC / SAC lenses. Check the Fisba homepage for a great variety of them..

Hello, Dr. Rehn

Thank you very much for your guidance

According to your answer, I searched about FAC and SAC lenses. The focal length and diameter of these lenses are very small. My goal is to design a collimator with an output beam diameter of about 5 cm.

Scale it up and look for ordinary cylindrical lenses !

In your opinion, using a single cylindrical lens is the most optimal solution?

Two of them like FAC and SAC, just bigger.

Thank you so much

I have had great results with just a single plano convex lens and putting the laser at the focal point. (This only works on small distances ≈ 0.5m)

@Alejandro Bladder

I want to achieve a total divergence of 0.2 degrees. In ideal conditions, this value can be reached, but in reality, there are tolerances during mechanical construction and assembly that make it difficult to reach this value.For example, in simulation (Zimax), in some cases, one millimeter increases the deviation and displacement of the laser relative to the center of divergence by 100 times.. What is your suggestion to reduce the impact of mechanical tolerances?

Thanks alot

Dear,

The diode laser of the optical device is intended to form a light spot of a predetermined shape on a target, which is part of a wavelength conversion device, from a light beam emitted from a laser diode and scanned by a scanner. The laser diode emits the beam along an optical axis, a slow axis and a fast axis, pairs of which are orthogonal. So if you want a smaller collimating laser beam, you have to accept a larger divergence; On the contrary, if we want to keep the light collimation over a long distance, it needs to get a larger beam size. The laser beam is focused by the focus lens. The focus lens acts like a magnifying glass and sunlight. With a 55mm lens, the laser beam passes through the lens and converges on the smallest point about 55mm from the edge of the lens.

The laser beam is focused to the smallest size.

@Alliance Tony-Mayeko

Hello Dr. Tony-Mayeko

Of course you are right. Beam collimation is the same focus at a distance.And ideally it can be done with one lens. But my problem is more with mechanical errors. And I am looking for an optimal system or method to reduce the effects of mechanical tolerances.I think I should edit my question or start a new discussion with this topic.

Thank you for your complete explanation.