Fiber vs MOPA — what’s the difference?

Both are 1064nm fiber lasers. A standard Q-switched fiber has a fixed pulse duration; a MOPA source lets you tune pulse duration and frequency independently. Same metals, different palette.

The tunability is what buys color marking on stainless and titanium, gentler marks on anodized coatings, and cleaner results on tricky alloys. For tags and deep engraving a Q-switched fiber is fine; for color and finish control, MOPA is the class to specify.