Fig. 1. Changes in market size and growth rate of laser cleaning equipments in China

Fig. 2. Typical applications of laser cleaning in the aerospace field. (a) Aircraft engine oil filter cleaning^[49]; (b) aircraft skin cleaning^[54]; (c) removal of thermal barrier coating on blade surface^[51] [(c1) before cleaning, (c2) after cleaning]; (d) organic molecule cleaning for aircraft engines^[52] [(d1) before cleaning, (d2) after cleaning]; (e) laser cleaning of the receiver surface^[55] [(e1) before cleaning, (e2) after cleaning]; (f) engine surface cleaning and simulation of thermal stress distribution^[53]; (g) removal of rust in the airway of aircraft engines^[50] [(g1) before cleaning, (g2) after cleaning]; (h) engine high-temperature oxidation surface cleaning^[56] [(h1) before cleaning, (h2) after cleaning]

Fig. 3. Typical applications of laser cleaning in the automotive field. (a) Tire mold cleaning^[59] [(a1) before cleaning, (a2) after cleaning]; (b) laser cleaning of brake discs^[59]; (c) laser cleaning of brake pads^[59] [(c1) before cleaning, (c2) enlarged image, (c3) after cleaning]; (d) cleaning of tire liner release agent^[63] [(d1) before cleaning, (d2) after cleaning]; (e) car body paint cleaning^[60]; (f) weld cleaning^[31]

Fig. 4. Typical applications of laser cleaning in power industry. (a) Cleaning of active and static contacts of isolation switch^[66] [(a1) before cleaning, (a2) after cleaning]; (b) cleaning of transmission line surface by unmanned aerial vehicle combined with laser cleaning device^[67]; (c) laser cleaning of insulators^[67] [(c1) before cleaning, (c2) after cleaning]; (d) de icing test for transmission lines^[68]

Fig. 5. Typical applications of laser cleaning in cultural relic protection. (a) Ancient Roman marble Odysseus sculpture^[69] [(a1) before cleaning, (a2) after cleaning]; (b) bronze sculptures of the university of Illinois^[70]; (c) ancient Egyptian glassware^[71] [(c1) before cleaning, (c2) after cleaning]; (d) 15th century panel oil painting Christ before Pilate^[72] [(d1) before cleaning, (d2) after cleaning];(e) 19th century gilded wood frame^[73]

Fig. 6. Typical applications of laser cleaning in semiconductor industry. (a) Silicon slit sidewall silicon dioxide particles^[74] [(a1) before cleaning, (a2) after cleaning]; (b) copper particles on silicon wafer^[75] [(b1) before cleaning, (b2) after cleaning]; (c) aluminum oxide particles on silicon surface^[76]; (d) gold layer deposited on fused silicon substrate^[77]; (e) polystyrene latex nanoparticles on silicon wafer at different angles of the double beam^[78]

Fig. 7. Typical applications of laser cleaning in the optical field. (a) Cleaning of uranium dioxide particles on optical lens^[79] [(a1) before cleaning, (a2) after cleaning]; (b) carbon deposition on Rh film surface^[80] [(b1) before cleaning, (b2) after cleaning]; (c) cleaning of deposited layer of HL-2A Tokamak^[81] [(c1)surface morphology of the contaminated mirror after plasma irradiation, (c2) mirror morphology after 50 pulse ablation]; (d) cleaning of carbon deposited layer of HL-2A Tokamak^[82] [(d1) over cleaning, (d2) complete cleaning]; (e) cleaning of silicon dioxide film on the surface of large-diameter vacuum isolation sheet^[83] [(e1) before cleaning, (e2) after cleaning]; (f) comparison of ITER mirror sediment cleaning^[84]; (g) K9 glass substrate surface contamination cleaning^[85] [(g1) before cleaning, (g2) after cleaning]

Fig. 8. Number of SCI papers in the field of laser cleaning research of last 10 years

Fig. 9. Number of patent applications in the field of laser cleaning research of last 10 years