Photochromic properties of 1′,3′,3′‐trimethyl‐6‐nitrospiro[2H‐1‐benzopyran‐2,2′‐indoline] doped in PMMA and epoxy resin thin films

Photochromic properties of 1′,3′,3′‐trimethyl‐6‐nitrospiro[2H‐1‐benzopyran‐2,2′‐indoline] doped in PMMA and epoxy resin thin films