Spiricon, Inc. has discovered a time saving method to tune lasers in real time. One of the most popular instruments to measure the M2 (or beam focusability factor) has been Spiricon's M2-200, which shows beam profiles and calculates M2 according to the ISO 11146 method. This instrument has both increased the reliability and reduced the time needed to make the measurement, proving its worth in both research labs and manufacturing facilities. With a new method developed at Spiricon, technicians can use this instrument to calculate laser beam diameters at any point along a caustic while they make adjustments to the laser.