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FAQ About Fiber Laser

Frequently Asked Questions about Fiber Lasers

1. I’m currently using lamp pumped YAG lasers in my application. What advantages would switching to fiber lasers offer me?


• Electrical efficiency of greater than 28 % wall plug efficiency vs. 1.5% to 2% for lamp pumped YAG
• Cost savings from no replacement of flash lamps: Long life telecom grade single emitter diodes lifetimes greater than 100,000 hours used in fiber lasers vs. flash lamps
• Fixed spot size and spot profile at all power levels
• Maintenance free or low maintenance operation
• Minimal spare parts
• Air-cooled or minimal cooling requirements
• Substantial reduction in laser footprint
• Longer working distance
• No requirement for alignment
• No warm-up/instant on

 

2. Your competition claims that back-reflection is a problem with fiber lasers. Is this true?


• These statements come from people not familiar with fiber laser technology. Our multi-kilowatt low mode fiber lasers are not susceptible to back reflection issues if the appropriate delivery fiber is utilized. With single-mode lasers they in most cases do not have a problem, unless highly reflective materials are processed. However, if the back reflection is too high, the units sense the reflection and automatically shut down. The addition of an isolator eliminates this issue. IPG have numerous units in the field cutting and welding highly reflective material such as copper and aluminum on a production basis.

 

3. How can you be so confident that your diodes have this life-time?


• IPG Photonics percent tests 100% of their diodes before they are certified for a laser or amplifier. Duration of the test generally is longer than 1,500 hours when diodes are operated at stressed conditions, greatly elevated temperature and current. If the diodes pass this test with no drop off in power they are certified for usage in our devices. Whether the diode is used for a 10kW fiber laser for materials processing or a broad band fiber amplifier for telecom, the similar procedures are followed. IPG is now the largest manufacturer of single emitter multi-mode diodes with the most extensive diode test facility in the world. This is also backed up with over 650 multi-kilowatt fiber lasers now in production applications with many in operation over 5 years.

 

4. Can the same fiber laser both cut and weld?


• The same fiber laser can do cutting, welding, drilling and cladding. Many customers have purchased a fiber laser with a 2-way, 4-way or 6-way beam switch. For example, one leg will have a 100 micron fiber for cutting, a 200 micron for welding and 400 or higher for cladding or annealing. The power can be changed to a different level and switched to a new delivery fiber in a matter of milli-seconds. Delivery fiber can support multiple work stations of up to 200 meters apart.


 
5. Why are fiber lasers more efficient than other solid state and gas lasers?


• The answer is simple – the design of fiber lasers generates less heat and manages the heat they generate effectively. The quantum defect (that is the difference between pump and emission energy) is lesser for a Ytterbium diode pumped fiber laser (pumped at 980 nm) than a Nd: YAG diode pumped laser (pumped at 808 nm). Also, the optical to optical conversion efficiency of fiber laser is typically 70-80%, as compared with approximately 4% for lamp pumped YAGs, and approximately 40% for diode pumped YAGs and disk lasers. Because the light is always contained in a fiber, there are no additional sources of the loss inside the laser cavity.

 

6. How much can I save if I switched to fiber lasers?


• Users can save significant savings from using fiber lasers in their production. The amount you can save depends upon many things including your current process, materials, production environment, electrical and labor costs. Here are some of the savings:

 

a. Higher Wall Plug Efficiency: Fiber lasers have unrivalled efficiency when compared to existing conventional laser technologies:
Type Wall Plug Efficiency

 

Type
Wall Plug Efficiency
Fiber Laser Ytterbium (Yb)
28%+
Lamp-pumped YAG
1.5% - 2%
Diode-pumped YAG
10% - 20%
Disc
15% - 25%
CO2
5% - 15%

 


b. Cooling: The efficiency of the fiber laser also contributes to lower cooling requirements, which contributes to lower electrical usage. Lower power fiber lasers require only air cooling. Higher power fiber laser require water cooling that is generally more simple and less costly than for equivalent alternative laser technologies. Cooling also depends upon your particular production environment.

 

c. Consumables/Replacement Parts: Because of the highly efficient design of fiber lasers (better thermal management) and the use of telecom-grade single emitter pump diodes in our fiber lasers, you can save on replacement parts (such as lamps and diode bars), labor and production down time. Many lamps and diode bars used in YAGs have estimated lifetimes of 2,000 hours and 20,000 hours, respectively. These are a fraction of the MTBF of IPG’s single emitter diodes of > 100,000 hours which mean that for the life of the fiber laser, you should not have to replace the diodes. In the all solid-state fiber-to-fiber design of IPG’s lasers, you save even further because there are no optics to adjust or maintain, such as resonators mirrors, crystals, fluids and filters, as in conventional lasers.

 

d. Maintenance: Fiber lasers require no or low maintenance, depending on the output powers and other factors, as compared to conventional lasers. There are no optics to align and no warm up-times, as well as consumables/replacement parts. As a result, you can save substantial sums on maintenance.

 

e. Capital costs: With fiber lasers, the same laser can cut, weld and drill, allowing you to lower your investment costs as compared to purchasing and maintaining different lasers and laser systems for each of these functions.