Evolution of Industrial Lasers: Persistence of Marshall Jones leads to revolutionary changes in additive manufacturing
The innovative work of Jones that led to his induction into the National Inventors Hall of Fame is on display in U.S. Patent No. 4676586, titled Apparatus and Method for Performing Laser Material Processing Through a Fiber Optic. Issued on June 30th, 1987, the patent protected an improved method of delivering laser energy to perform metal processing by generating a near infrared or visible wavelength pulsed laser beam, providing a single fiber optic with a quartz core having a diameter of less than 1,000 micrometers as well as cladding and protective shielding for the core end, focusing the laser beam onto the end of the core on a small spot with a diameter less than the core diameter at an including angle of less than 24°, coupling the beam into the fiber optic through air-core and core-cladding zones to transmit energy with a peak power in the kilowatt range, and then focusing the laser beam emerging from the fiber optic onto a workpiece at a power density sufficient for metal processing. The invention resulted in a laser beam delivery system with minimal optical losses and improved freedom of laser beam manipulation capable of being robotically controlled.