High Power Fiber Lasers - Laser Symposium · the German national funding initiative “Integrated...
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High Power Fiber Lasers Ulrich Hefter
Transcript of High Power Fiber Lasers - Laser Symposium · the German national funding initiative “Integrated...
High Power Fiber LasersUlrich Hefter
400µ x 1mm
Density 2.5g/cm3
Melting point 1500 C Heat capacity 0.8kJ/kg C
Melting energy = Volume*Density*Heat capacity*Melting point
~ 0.5J or 5W over 1/10 second
No Tolerance for Losses
Fiberlaser Basics ‐ Glass
Typical fiber specs. Core diameter 20±2µ Cladding diameter 400±15µ Centricity 2µ
Worst case losses Core 33% 330W@1kW Cladding 14% 140W@1kW Centricity 5% 50W@1kW
Cladding shape Active octagonal Passive round
Fiberlaser Basics ‐ Fiber
Matched Fibers Needed
Active fiber 200µ, NA 0.46 BPP 46 mm x mrad 400µ, NA 0.46 BPP 92 mm x mrad
BPP conservation Sqrt(N) * r * Nap ≤ R * Naa
Pump modules 19 x 100µ NA ≤ 0.21 typ. 0.15 up to 100W 7 x 200µ NA ≤ 0.35 typ. 0.22 up to 500W
Matched Pumps Needed
Fiberlaser Basics ‐ Pumping
Fiberlaser – Breadboard
Laser Diodes
Active FiberPump Coupler
FBG
Output Fiber
Fiberlaser – Breadboard
Mode Stripper ? Power Meter
(fwd/bwd) ? Pilot Beam ? Power
Combiner ? Beam Switch ? Taper ? Mode Mixer ? BWD Isolator ?
ROFIN Fiberlaser – Strategic Partnership
Output Fiber
Fiber coupleddiode‐laser
pump modules
ROFIN Fiberlaser ‐ Architecture
12x Passively CooledPump Modules
12x Pump Fibers
Output Fiber
ROFIN Fiberlaser – Fiber Laser Unit
ROFIN Fiberlaser – Fiber Laser Unit
ROFIN Fiberlaser – Fiber Laser Unit
Compact modular design
• 19 inch• 3 rack units
Output Fiber
ROFIN Fiberlaser ‐ Fiber Laser Unit
Internal Monitoring& Safety Board
M2 = 1.1 @ 1.2 kW
opt‐opt > 80 %
ROFIN Fiberlaser – 1 kW Single Mode
FLC
4:1SM to MM Combiner
4x 1kW FLU
4kW Output
ROFIN Fiberlaser – Scalability MM
ROFIN Fiberlaser ‐ FL020C, FL030C, FL040C
BPP = 1.8 mm x mrad 50µ FiberBPP = 3.6 mm x mrad 100µ Fiberopt-opt > 80 %
ROFIN Fiberlaser – Products
FL 040
FL 020C, FL 030C
FL x50C, FL 010C
ROFIN Fiberlaser – eShutter
• Certified Safety System by accredited laboratories
• In compliance withEN ISO 13849‐1 / ‐2
LPS FLM/FLC
Oscillator„Higher power pumps“
MOPA„More pumps“
ROFIN Fiberlaser – Scalability SM
M2 = 1.3 @ 2 kW M2 = 1.7 @ 2 kW
2kW SM Oscillator vs. MOPA
2kW SM Oscillator vs. MOPA
Oscillator MOPA
10m output fiber 3m output fiber
Pulsed Laser – Synergies
+ =
E‐Line DYxxx DQ01020W 1kW 1kW30ns cw 38ns1mJ 150mJ
Pulsed Fiberlaser – Synergies
ns seeder
1mJ amp
Pulsed Fiberlaser – 1mJ
0
50
100
150
200
250
300
350
400
0 50 100 150 200 250 300 350 400
Pow
er [W
]
Rep. Rate [kHz]
Power vs Rep. Rate
Power vs Rep. Rate
Rofin fiberlaser archcitecture provides main cw power levels for industrial applications
Scaling to higher power by• Increased power of basic units• Cascading of combined power sections• All in fiber power combination
Feasibility of pulsed high power fiber lasers for industrial
applications demonstrated
Summary
A part of this work was sponsored by the German Federal Ministry of Education and Research (BMBF) withinthe German national funding initiative “Integrated Optical Components for High Power Laser Beam Sources(INLAS)” and “Material Processing with Brilliant Laser Beam Sources (MABRILAS)”.
Additional parts of this work were supported with funding from the Leadership in Fiber Laser Technology(LIFT) project under the 7th Framework Program of the European Commission.
Acknowledgement
To be continued…Thank you for your attention andsee you in Hamburg…
