Flexible distributed feedback lasers based on nanoimprinted cellulose diacetate with efficient multiple wavelength lasing

• Published in: Npj flexible electronics Vol. 3; no. 1; pp. 1 - 7
• Main Authors: Smirnov, José R. Castro, Sousaraei, Ahmad, Osorio, Manuel R., Casado, Santiago, Hernández, Jaime J., Wu, Longfei, Zhang, Qi, Xia, Ruidong, Granados, Daniel, Wannemacher, Reinhold, Rodriguez, Isabel, Cabanillas-Gonzalez, Juan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03-09-2019; Nature Publishing Group; Nature Portfolio
• Subjects: 639/624/1020; 639/624/399/1028; Accuracy; Cellulose; Cellulose diacetate; Chemistry and Materials Science; Distributed feedback lasers; Electronics and Microelectronics; Emission; Engraving; Instrumentation; Lasers; Lasing; Materials Science; Optical and Electronic Materials; Polymer Sciences; Polymers; Spin coating; Substrates; Thresholds
• ISSN: 2397-4621; 2397-4621
• DOI: 10.1038/s41528-019-0062-4

Here we present the assembly of novel transparent all-polymer distributed feedback (DFB) lasers. Flexible and highly transparent cellulose diacetate (CdA) was employed as substrate on which gratings with different periods were engraved by thermal nanoimprinting with high fidelity. Highly luminescent conjugated polymers (CP), poly (9,9-dioctylfluorene) (PFO), poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT), and a blend of F8BT and poly(3-hexylthiophene)-poly(9,9-dioctylfluorene-alt-benzothiadiazole) (P3HT:F8BT) were deposited by spin coating onto the nanostructured plastic surfaces, giving rise to perpendicular single-mode lasing emission in the blue, green, and red wavelength ranges, respectively. These lasers show linewidths below 1 nm and low thresholds (≈6 μJcm
−2
for blue and red lasing emission), comparable to other state-of-the-art lasers obtained from similar optical gain materials on rigid substrates. The followed strategy is scalable and versatile, enabling the development of large area nanoimprinted DFB lasers (>1cm
2
) on plastic, which is highly relevant for applications in various markets.
Multi-colored polymer lasers
Highly luminescent polymers can work as lasers when incorporated with suitable cavities and now the nano-imprinting makes the fabrication much cheaper and more scalable. An international team led by Prof Juan Cabanillas-Gonzalez from Madrid Institute for Advanced Studies in Nanoscience, Spain demonstrates transparent all-polymer distributed feedback (DFB) lasers in blue, green, yellow and red. The most important step is to make sub-wavelength periodic gratings on the flexible and highly transparent cellulose diacetate substrates by thermal nano-imprinting with high fidelity to maximize the constructive interference effect. As a result, these lasers show narrow linewidths below 1 nm at low power thresholds of several μJ cm^−2, which is comparable to conventional approaches. This large area nano-imprinting method is scalable and adaptable and it enables stackable multi-colored laser emission.