optical models for the 'G' lenses

[steve001]

I dont think the planar convex is able to focus to a spot from the diverging output of the diode, but would work after collimation. Having a single element would simplify setup and reduce possible errors.

It certainly can.

 

[dbrown2k]

Ah yes true enough. Unfortunately the D 25mm, 30mm FL has really large separation distances between the diode; 40mm from diode to lens and then 80mm to get down a spot.

The other plot is estimated asphere (all coefficients zero) with same diameter (6.33mm) and focal length (4.02mm) as the laserlands G2 lens drawing. Which is 3.2mm distance from diode to lens and then 10mm from lens to focal point, with a spot diameter of 122um. So that looks promising for the G2.

 

[dbrown2k]

So think i've found a possible basis design that the G2 is modelled on. Edmund optics has an asphere lens for 405nm, D6.325mm, FL4.02 [https://www.edmundoptics.com/optics/optical-lenses/aspheric-lenses/Blue-Laser-Collimating-Aspheric-Lenses/ Stock #83-990, and they have a zmax file that can be downloaded and imported into WinLen3D basic.

This lens uses D-LaK6 substrate and the laserlands version uses L-BAL35 so i've substituted the materials and changed the lens radius to bring the focal length back to 4.02mm.

Is this a valid approach? The results look good for this G2 lens, but unsure how accurate this is.