Photonik
Research
Publications
German
Diode laser
What:
Improvement of beam quality of high power diode lasers
Why:
Direct applicability of diode lasers also at high optical powers
How:
Exteral resonators
Starting point:
Beam quality
physical limit M
2
³
1
present values for high power diode lasers: M
2
=50
present values for bars of 25 diodes: M
2
=2500
Ansatz:
single laser
bar laser
reduce divergence
operation in fundamental mode of single broad area diode laser in external resonator
reduce beamwaist
coherent operation of 25 lasers of bar in external resonator with coupling
Resonators
Results
Fundamental mode operation achieved: M
2
=1.03 at P
opt
=0,4 W
Power density improved by of 25 lasers factor 12.
alternately: M
2
=2,7 at P
opt
=1,1W
Design und setup of coupling resonator
Experimental proof of coupling of 25 lasers
coherent laser operation
M
2
»
60 (improvement by factor 40.)
Danilo Skoczowsky
German
