A common configuration, for example for stabilizing a single beam, consists of 1 x position sensor, 2 x actuators and 1 x control electronics. The system can be extended with further components. The range of possible components is shown below.

Aligna systems can be arranged in almost any desired modular way according to application requirements and can be expanded at any time. A system always consists of the basic elements angle/position sensors, control electronics and actuators (beam steering). In addition, the program includes, for example, beam shutters, fiber alignment options and much more. If you have a special request, please do not hesitate to contact us. A large number of components from our program has been developed as a result of customer requests.

Instabilities with laser beams can occur in up to four spatial directions: translational (X and Y) and rotational (Φ and θ). Since the motions occur in all directions, both forward and backward, they are sometimes referred to as 4 and 8 degrees of freedom.

Often the degrees of freedom are interdependent. For example, a pure angular drift leads to a combination of angular and positional motion after a longer propagation distance. The longer the beam paths become, the more obvious this dependence becomes.

Instabilities for laser beams can occur in up to four spatial directions: X, Y, Φ, θ.

For example, consider a mirror holder that drifts by 100 µrad due to changes in room temperature. This angular drift leads to a beam deflection of 0.1 mm already after 1m travel distance and 1 mm deflection after 10m travel distance.

To compensate for the combination of angular and positional drift, a combination of positional and angular correction is required. In the example (figure) this is done by a 4D correction using two 2D mirror actuators.

To measure the angular and positional displacement, two 2D sensors are required consequently, one sensor for the X and Y positions and another for the angular positions Φ and θ. A 4D detector, such as the PSD 4D from TEM Messtechnik, conveniently combines both types of sensors in one housing. Based on the sensor data, the Aligna stabilization system is able to independently perform the correction control of the actuators.

To compensate for the combination of angular and positional displacement, a combination of positional and angular correction (4D correction) is required.

µAligna

• Very compact design (210 x 125 x 90 mm)
• Fully automatic, high-precision laser beam alignment
• Compatible with all Aligna system actuators and detectors

Aligna (19″ rack mounting)

• suitable for 19″ rack mounting (484 x 343 x 150 (3 HU) mm)
• Fully automatic, high-precision laser beam alignment
• Compatible with Aligna system actuators and detectors

Depending on your application, our staff will suggest the most suitable variant of the control unit (µAligna or HE-Rack variant).

The 4D stabilization system is the most common application for beam stabilization. The position of the laser spot on the target is to be kept stable. This is (typically) achieved by controlling 2 x active mirrors and by 1 x position & angular sensitive detector.

Similar to 1-beam stabilization, but with additional position control, which simplifies beam search and beam guidance for very long paths. Well suited for beamlines or for beam delivery across laboratories.

If several beams have to be positioned and kept stable on the same spot, a multi-beam stabilization system is appropriate.

Autofocus and point stabilization are the advantages of the “multi-drill” from TEM Messtechnik. It is particularly useful for material processing applications and everywhere where the focus of the laser spot plays a crucial role.

A typical application for Aligna systems is the stabilization of a beam focused into a hollow fiber or capillary using a lens with a relatively long focal length (f = 0.3 m … 2 m).

Fast setting of high coupling efficiency is achieved by automatic fiber coupling. Maximum intensity can be achieved and secured at any time. Highly convenient beam coupling is made possible by a scan mode, which allows fast scanning of the fiber input.

Beam switching allows the laser beam to be switched between different workstations, and the (almost) full laser power is available for the selected application. With a beam sharing system, several workstations can be operated simultaneously with one light source.

The position of the laser spot on the target must be kept stable, even if the laser source and application are located on different tables. Beam stabilization solutions are also suitable for areas with restricted access, e.g. S3 or S4 bio-labs, clean rooms or radioactive areas.

Beam stabilization, precise focus control and beam parallelization along long travel paths are required for common laser material processing systems. Laser beam stabilization in gantry systems where the beam is in motion is a very typical application for Aligna systems.

As with the gantry application before, but here it is about beam stabilization with moving focusing heads in (at least) two directions, X and Y, and sometimes also in Z.