Uni-Potsdam Physik - Uni-Potsdam
Photonik - Physik - Uni-Potsdam
Photonik

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 M2 ³ 1
  • present values for high power diode lasers: M2=50
  • present values for bars of 25 diodes: M2=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: M2=1.03 at Popt=0,4 W
  • Power density improved by of 25 lasers factor 12.
  • alternately: M2=2,7 at Popt=1,1W
  • Design und setup of coupling resonator
  • Experimental proof of coupling of 25 lasers
  • coherent laser operation
  • M2 » 60 (improvement by factor 40.)
Danilo Skoczowsky