Automated alignment of fast-axis collimator lenses for high-power diode laser bars

Thomas Westphalen; Stefan Hengesbach; Carlo Holly; Martin Traub; Dieter Hoffmann

doi:10.1117/12.2041245

7 March 2014 Automated alignment of fast-axis collimator lenses for high-power diode laser bars

Thomas Westphalen, Stefan Hengesbach, Carlo Holly, Martin Traub, Dieter Hoffmann

Proceedings Volume 8965, High-Power Diode Laser Technology and Applications XII; 89650V (2014) https://doi.org/10.1117/12.2041245
Event: SPIE LASE, 2014, San Francisco, California, United States

Abstract

The active alignment of fast axis collimator lenses (FAC) is the most challenging part in the manufacturing process of optical systems based on high power diode laser bars. This is due to the high positioning accuracy in up to 5 degrees of freedom and the complex relations between FAC misalignment and properties of the resulting power density distribution. In this paper an experimental approach for FAC alignment automation is presented. The alignment algorithm is derived from a beam propagation model based on wave optics. The model delivers explicit relations between FAC misalignment and properties of the distorted power density distribution in the near and far field. The model allows to calculate the FAC misalignments and to correct them in one or multiple steps. The alignment algorithm is tested with a demonstrator system. The demonstrator contains an optical system which allows a real time analysis of the near field and far field power distribution of individual emitters. For the tests two different types of FAC lenses and high power diode laser bars are used. The FAC lenses are prealigned within a range of ±50 μm and 0.5 degree around the suitable position. During the automated alignment process the translational and rotational remaining misalignment and the properties of the far field power density distribution are recorded. The experimental results are evaluated regarding reliability and flexibility of the presented FAC alignment algorithm.

Citation Download Citation

Thomas Westphalen, Stefan Hengesbach, Carlo Holly, Martin Traub, and Dieter Hoffmann "Automated alignment of fast-axis collimator lenses for high-power diode laser bars", Proc. SPIE 8965, High-Power Diode Laser Technology and Applications XII, 89650V (7 March 2014); https://doi.org/10.1117/12.2041245

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available