Uncovering Cause of Bad Welds in Fiber Delivery System
Upon the installation of new laser processing equipment, it is necessary to test and verify the performance of the laser system to insure it meets specification. Just relying upon the test results of the laser prior to shipment is not sufficient – shipping issues, handling problems, and reinstallation activities can all affect the final performance of the equipment. For these reasons, testing the equipment once set up for manufacturing is essential and critical to have the confidence the intended application will achieve or exceed the specification.
When installing a fiber delivered laser system, checking the quality of the delivered beam is important. The beam quality can be checked at the couplers and verified through the optics. But only when the final beam is delivered to the work surface can the combined effect of these variables be detected and validated.
In this application, the manufacturer reported the new laser had the correct size fiber, the proper beam quality, and the specified beam measurements as required for the application. To verify these statements, the Ophir-Spiricon BeamCube was installed under the optics head; this instrument allows for the measurement of the laser beam profile (size, shape, and intensity), as well as the average power of the beam output and the temporal profile of the pulse shape – all provided simultaneously to the customer’s computer.
The results of the initial laser performance test reported that the power and temporal profile measurements were both within specification limits. However, the Beam Profile showed a severely defective condition – forcing the beam to produce a donut-type image rather than a fully homogenous beam profile – a condition that, left uncorrected, would produce totally unacceptable welds. Through the BeamCube, the beam analysis was conducted using the Ophir-Spiricon BeamGage Professional software following an ISO-approved measurement approach, as well as accurate 2D and 3D images of the distribution of the energy.
This factual and visual information, verified after several tests, was provided to the laser manufacturer. Upon reviewing this information and the associated images, the manufacturer agreed that there was a likely problem with the fiber delivery system, and sent in a laser service technician immediately. The service technician, after investigating the laser system thoroughly, installed a new, replacement fiber. The Ophir-Spiricon BeamCube was reinstalled, the same laser parameters keyed into the system. Once operational, the proper beam profile met specifications.
The acceptance test of this laser system was accelerated using the Ophir BeamCube beam diagnostic equipment supported by the BeamGage Professional software. Through these tools the original setup problem with the laser was quickly identified. This information was used to support the existence of this issue, which the laser manufacturer initially doubted. Upon review of the beam profile data, the laser manufacturer dispatched a service technician to correct the condition. The laser system was then brought online within days, its performance verified to meet the original specification to both management as well as the vendor. This allowed the equipment to be accepted and validated by manufacturing and moved into production more quickly than it would have otherwise.
