Transcript Constructing a High Power Single

High Power Double-Clad Fiber Laser
Colin Diehl & Jered Richter
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Single-Mode Fiber
Multimode Fiber
6 µm core / 125 µm cladding
High Beam Quality
Low Propagation Loss
Lower Power Pumping
Expensive Pumping
50 µm core / 125 µm cladding
Higher Power Pumping
Inexpensive Pumping
Poor Beam Quality
High Propagation Loss
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Double-Clad Fiber
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Laser light propagates in single-mode core
Pump light propagates in inner cladding
Pump Laser – 50 W 915 nm Laser Diode
Protection Circuit
Erbium-Ytterbium Co-Doped Fiber
Optical Fiber Modes
Mode Scrambling
Experimental Results
• Maximum output power of 1.384 W
• Slope efficiencies increased 10%  13%  15%
Experimental Results
• Small changes due to inconsistent polish quality
• Coupling optimization not crucial
Linewidth
• Monochromator resolution of 0.3 nm
• FBG bandwidth of 0.1 nm
Beam Profile
Beam waist = 86 µm
•M2 = 1.10
•Rayleigh length = 3.3 mm
Future Improvements
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Improve output power:
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Increase EYDF length
Pump with 975 nm laser
Additional pump lasers
Improve linewidth
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Incorporate Fabry-Perot cavity
Or incorporate diffraction grating