Realizing a flexible and wavelength-tunable random laser inspired by cicada wings

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2024-04, Vol.12 (16), p.571-577
• Main Authors: Chou, Chia-Jung, Abe, Ayano, Tang, Jian-Fu, Lin, Tzu-Chau, Kuo, Chi-Ching, Lin, Ja-Hon, Adachi, Chihaya
• Format: Article
• Language: English
• Subjects: Dyes; Image contrast; Infrared lasers; Lasers; Light sources; Near infrared radiation; Positron emission; Silk fibroin; Substrates; Tunable lasers
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d3tc03576j

A bio-tissue-inspired random laser (RL) has been successfully demonstrated using a dye-covered silk fibroin replica film (DC-SFRF) fabricated through soft lithography of a cicada's wing. Thanks to the increased light scattering between the nanopapillate structures of the DC-SFRF, the RL exhibits a lower lasing threshold, higher slope efficiency, and broader angular emission compared to those of the dye-covered silk fibroin film (DC-SFF). The low spatial coherence NIR RL can also serve as a suitable light source in bio-diagnosis to generate a low speckle noise image with a contrast of approximately 0.040. By employing flexible PET as a substrate, we have demonstrated the flexibility of the near-infrared random laser (NIR RL) through the application of mechanical stress to alter the distribution of nanopapillate structures on the surface of the replica film. As the curvature increases, the DC-SFRF RL exhibits a blue shift of 13.3 nm in the emission spectrum and a further reduction in the speckle contrast to 0.031. A bio-tissue-inspired random laser (RL) was successfully demonstrated with a dye-covered silk fibroin replica film (DC-SFRF), created using soft lithography from a cicada's wing. By applying mechanical stress to modify the nanopapillate structure distribution on the film's surface, the DC-SFRF RL exhibits a 13.3 nm blue shift and a decreased speckle contrast.