Recent brightness improvements of 976 nm high power laser bars

Alexander Bachmann; Christian Lauer; Michael Furitsch; Harald König; Martin Müller; Uwe Strauß

doi:10.1117/12.2262985

22 February 2017 Recent brightness improvements of 976 nm high power laser bars

Alexander Bachmann, Christian Lauer, Michael Furitsch, Harald König, Martin Müller, Uwe Strauß

Proceedings Volume 10086, High-Power Diode Laser Technology XV; 1008602 (2017) https://doi.org/10.1117/12.2262985
Event: SPIE LASE, 2017, San Francisco, California, United States

Abstract

Pump modules for fiber lasers and fiber-coupled direct diode laser systems require laser diodes with a high beam quality. While in fast axis direction diode lasers exhibit a nearly diffraction limited output beam, the maximum usable output power is usually limited by the slow axis divergence blooming at high power levels. Measures to improve the lateral beam quality are subject of extensive research. Among the many influencing factors are the chip temperature, thermal crosstalk between emitters, thermal lensing, lateral waveguiding and lateral mode structure.

We present results on the improvements of the lateral beam divergence and brightness of gain-guided mini-bars for emission at 976 nm. For efficient fiber coupling into a 200 μm fiber with NA 0.22, the upper limit of the lateral beam parameter product is 15.5 mm mrad. Within the last years, the power level at this beam quality has been improved from 44 W to 52 W for the chips in production, enabling more cost efficient pump modules and laser systems.

Our work towards further improvements of the beam quality focuses on advanced chip designs featuring reduced thermal lensing and mode shaping. Recent R&D results will be presented, showing a further improvement of the beam quality by 15%. Also, results of a chip design with an improved lateral emitter design for highest brightness levels will be shown, yielding in a record high brightness saturation of 4.8 W/mm mrad.

Citation Download Citation

Alexander Bachmann, Christian Lauer, Michael Furitsch, Harald König, Martin Müller, and Uwe Strauß "Recent brightness improvements of 976 nm high power laser bars", Proc. SPIE 10086, High-Power Diode Laser Technology XV, 1008602 (22 February 2017); https://doi.org/10.1117/12.2262985

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