Laser Module in MOBeam
If you assume the VG-L7X manual had the wrong units for focus, i.e CM vs MM.
Then I have a G8 lens in my unit? Is this a coincidence?
The smallest beam spot also explains why the dot looks rectangular (laser diodes do not operate in TEM00).
However, at the focal point, the intense area of the beam is round.
Finding The Focal Point
The Empirically Derived MoBeam Focal Distance
Focus Using a USB Microscope
- Make a target by painting a substrate with flat black paint. I used a round steel medallion. A black surface makes it easier to see the most intense part of the beam.
- Put on your laser safety glasses
- In Vigoworks turn on the "weak beam"
- Place the microscope on its stand in front of the laser module focussed on the beam.
- Adjust the entire module up/down to get the smallest round spot.
- With the module fixed in position adjust the lens until the smallest round spot is achieved.