What is an F-theta lens?

F-theta lenses are designed to focus a laser beam onto a planar image plane. They are often used in a scanning system with a Galvanometer scanner. The galvanometer is responsible for beam deflection in one direction and the second one for the perpendicular direction. 

What are F-theta lens used for?

F-Theta lenses are specially designed for laser material processing applications. High Laser Damage Threshold AR coatings provide excellent throughput and durability.  Typical focusing lenses offer an optimized focus for a single spot,  however F-Theta lenses provide an optimized focus at many locations in the scan field on  the workpiece. F-Theta Lenses are used in applications such as laser marking, bar code readers, laser micromachining, laser scanning, and many other laser applications in the microelectronics, semiconductor, automotive and medical industries.

What exactly is a Galvo Head?

Galvanometer scanner allow for 3-axis laser marking works. 3-axis technology also benefits application-on-the-fly with moving targets, while in 3D-applications, the setup enables processing of non-flat parts or uneven surfaces and high power products. The pre-focusing deflection units meet customers application requirements for large processing fields with smaller spot sizes and allow the user to change the working distance, field and spot size with the same deflection unit.

In a pre-focusing deflection unit, the laser beam first enters a moving lens - the Linear-Translator-Module. A moving lens diverges the beam rapidly before it passes one or two focusing lenses. Then the beam hits a deflection unit that directs the laser towards any X-Y position inside the marking field.

In a deflection unit without focus correction, the focused laser spot at the centre of the field describes an arc when moved in either axis, creating a sphere of focused points above the working field. At locations away from the centre of the working field, the laser beam is not focused. This is due to the increased length from the lens to the workpiece, as the scanners direct the beam away from the centre of the field.

iLaser's 3D Laser Marking Machine System utilises a galvanometer scanner to efficiently create marking on object with a curve shape or surface that requires the usage of all 3 dimensions. Allowing for fine markings even on non flat surface materials.

The picture below shows our 3D Laser Marking Machine, click it for information on our 3D laser marking machine