Graph showing the history of maximum laser pulse intensity throughout the past 40 years. Simultaneously, at Columbia University, graduate student Gordon Gould was working on a doctoral thesis about the energy levels of excited thallium. When Gould and Townes met, they spoke of radiation emission, as a general subject; afterwards, in November 1957, Gould noted his ideas for a “laser”, including using an open resonator (later an essential laser-device component). Moreover, in 1958, Prokhorov independently proposed using an open resonator, the first published appearance of this idea. Meanwhile, Schawlow and Townes had decided on an open-resonator laser design – apparently unaware of Prokhorov’s publications and Gould’s unpublished laser work. In April 1957, Japanese engineer Jun-ichi Nishizawa proposed the concept of a “semiconductor optical maser” in a patent application.
The damage brought by MOPA fiber laser cleaning is very small, and the roughness value is close or even lower than the original surface . While cleaned by CW lasers, the roughness value will be 1.5X more than the original surface. For pulsed fiber lasers, a laser with lower frequency is more likely to hurt the substrate during the cleaning process, and a laser with a narrow pulse width could clean the paint more easily. It’s essential to balance the heat between cleaning the paint and melting the substrate . A pulsed fiber laser with a master oscillator power amplifier structure offers the advantage of precise heat control, which is a critical point during the cleaning process.
Rust remover chemicals can get the job done, but the health implications on their use outweigh their benefit. Such chemicals are not only harsh and abrasive but also emit intense fumes. You will need to wear protective gear such as a respirator, goggles and rubber gloves before using them.
Electrolysis leaves the rust particles floating in the water, which you later have to dispose of. In comparison, laser cleaning is a cleaner process as the rust particles are either vaporized or turned into plasma, leaving no evidence of waste. Scrubbing off rusted surfaces exposes you to impurities which could lead to respiratory complications. Laser cleaning, on the other hand, relies on the laser beam to ablate the surface. Comparison for the roughness of the surface after CW and MOPA pulsed fiber laser cleaning.