Fiber Laser Learning Lab 19 Back Reflection

Lotus Laser (lotuslaser.com) have lent me this MOPA 20 watt fiber laser to “play with”. Although I have a moderate understanding of laser technology and how constant power glass tube systems work, pulsing fibre laser marking machines are shrouded in deeper mystery than the glass tube machines. They have been designed for high speed marking and the technology has been well tried and proven. There are limited “tricks” that the pulsing laser technology can perform. You enter predefined parameters for each marking “trick” you wish the machine to deliver , then stand back in amazement. Most correspondents tell me they have bought their machine direct from China and received a machine and EzeCAD software, preloaded with a few default parameters. No other instructions beyond the EzeCAD manual are forthcoming. I must stress I am neither a teacher or expert in this field so you join me in my learning adventure with the warning that I have a simple but inquisitive mind and will probably make mistakes on my way to discovering the truth. I WILL oversimplify and maybe distort the scientific detail in my quest to build a simple picture of why and how this technology works. I am not trying to reverse engineer anything , just to break through the seemingly impenetrable “techno cotton wool” that surrounds this amazing piece of science. Useful Links: Why does light slow down in water? https://www.youtube.com/watch?v=CUjt36SD3h8 Why does light bend when it enters glass? https://www.youtube.com/watch?v=NLmpNM0sgYk Laser fundamentals III: Reflection back into laser | MIT Video Demonstrations in Lasers and Optics https://www.youtube.com/watch?v=JYzKNjD1zEU