Polymeric laser rods based on modified poly(methyl methacrylate) matrix synthesized by Fe^III complex catalyzed atom transfer radical polymerization with enhanced optical gain and Photostability

Abstract

The investigation of fabricating ultra‐compact solid‐state dye laser (SSDL) using N'N‐dimethylformamide (DMF) modified poly(methyl methacrylate) (PMMA) as the polymeric matrix was carried out. Atom transfer radical polymerization (ATRP) was introduced to manipulate the polymerization process of PMMA. By adjusting the additive amount of the FeIII complex (mixture of FeCl3 and 2,2’‐Bipyridyl (bPy)), the polymerization degree of PMMA was coordinated to gain better amplified spontaneous emission (ASE) properties of the embedded laser dye, Lumogen Orange 240 (LO). The ASE threshold of the FeIII complex catalyzed sample decreased as high as ~75%, from 225.3 ± 11.2 μJ cm−2 to 57.2 ± 2.9 μJ cm−2, comparing to that measured in common PMMA matrix. Additionally, a secondary dye, Stilbene 420 was added in the system for sharing excess excitation energy and oxidization damage, to overcome the photostability problem caused by the oxygen‐rich solvent, DMF. The operational lifetime of the resulted sample increased 200%, to the similar level of that without DMF component. Finally, by mechanical polishing and coating a thin film of silver at one end of the PMMA rod, an analogous Fabry‐Perot resonator was structured within the rod. Decent laser emission was obtained from the resulted SSDL without complex external cavities.