Some of Ophir's and Photonics Science best customers are experienced laser technicians all over the world.

The Lens failure analysis sums up a small portion of their knowhow and shares theirexperience in supporting laser systems frequent technical problems.

Lens spatters - When analyzing a lens failure, we distinguish between the upper side – CX and the lower side - Plano/CC.

Upper side (CX) - normally caused by contamination Originated in the machine side. Common types of contaminations :

- Unsealed Beam Delivery system (holes in the bellows) allows small particles to get into the Beam Delivery system, land on top of the lens and cause an uneven heat distribution.

- Oil/liquid contamination due to blocked filters, air separator etc.

• Lower side (CC/Plano) - this type of failure is usually caused due to the following reasons :
• Incorrect piercing pressure (too low), especially when cutting with nitrogen.
• Piercing too close to the surface of the plate
• Lens not in focus / inadequate cutting speed
• Metal sheet quality - mainly rust
• Low assist gas pressure.
• Thermal lensing caused by material stress, scratches on the lens, surface, metal spatters etc.

Spatters on the bottom of the lens
Metal spatters diffuses the laser beam, causing poor cutting quality and reduced lens life time.