Non-Disruptive, Low Loss In-Line Laser Beam Monitoring System for Industrial Laser Processing

By Michael Scaggs and Gilbert Haas

The BWA-MON (Beam Waist Analyzer MONitor) system is a “smart” focus head that provides “real-time” laser beam measurement, analysis and monitoring of low to very high power lasers in accordance with international standards ISO11146 and ISO13694 related to lasers without disrupting the laser beam in use and with minimal loss.

Prior to the genus of the BWA-MON, any measurement of a focused laser beam required a complete disruption of the beam; regardless of the application.  Laser manufacturers that develop or research lasers have to align the laser based upon arbitrary conditions, take it to an M-square measurement setup; make a measurement and if not desirable, go back and realign.  This process can take months to fully develop a system.  The BWA-MON aids the laser manufacturer by allowing them to adjust the laser in real time; so there is no need to remove the laser and test in another location and thereby greatly reduce development, setup and alignment time.  Previous methods available to measure the ISO laser beam parameters require the insertion of equipment that prevent the use of the laser during the measurement due to the size and method of measurement and most require minutes of time to make the measurement.  The BWA-MON simply provides a user the ability to actively monitor and measure a laser beam in accordance with ISO standards without disrupting the process beam in real time.

Since the BWA-MON provides the ISO laser beam metrics in real time, the possibility and effort to achieve six sigma quality control for a laser process is within the realm of possibility.  Any test or part manufactured or processed can have the laser metrics taken during that time available for analysis.  In the event a part is defective, the user can evaluate the data and see which parameter(s) of the ISO metrics has deviated from user set upper and lower limits for that parameter(s). The parameters can be tightened to prevent future loss.  When an ISO parameter falls out of the user entered limits, a signal is sent to an interlock circuit to shut down the system and warn the user.  The software identifies which parameter(s) have fallen out of range so corrective action can be taken thereby preventing defects and aid in the realization of six sigma quality control.  This process is especially beneficial for medical devices manufactured with lasers.  Typically a lot of parts are manufactured and a laser metrics measurement is made before and after the lot.  The problem is that perhaps the laser was fine before and after but what about during the manufacturing?  With the BWA-MON, should a part fail in the field in some way, the data taken during its manufacture can be called up and evaluated and any anomalies noted with the various ISO parameters.  This can greatly aid in long term reliability testing and help reduce liability.

Unit for multi-kilowatt lasers
Unit for multi-kilowatt lasers
Lower power version for under 500 watts
Lower power version for under 500 watts