Perylenediimide Polymers: Evaluating Third Harmonic Generation Responses for NLO Applications and Lasing Performance

Abstract In this study, the exceptional optical performance of the newly synthesized perylenediimide (PDI)‐based polymers is demonstrated. While the perylene‐based compounds are primarily recognized for their applications in photocatalysis and photovoltaics, the findings reveal their remarkable potential for a broader range of optoelectronic applications. Particular focus is placed on their nonlinear optical (NLO) behavior, with emphasis on the outstanding Third‐Harmonic Generation (THG) responses. Using the comparative Maker Fringes technique under near‐infrared (NIR) picosecond pulsed excitation, it is demonstrated that the third‐order NLO susceptibility parameter (χ (3) ) of the PDI polymers is 12–35 times greater than that of silica (χ (3) ≈ 2.0 × 10 −22 m 2 V −2 ). These exceptional NLO responses are further supported by Quantum Chemical Calculations (QC). Additionally, the studied polymers exhibit interesting Random Lasing (RL) behavior, which is correlated with their morphological features revealed by fluorescence microscopy techniques.