Monolithic Saturable Absorber with Gallium Arsenide Nanowires Integrated on the Flexible Substrate for Optical Pulse Generation

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Micromachines, Volume 14, issue 9
In this work, we demonstrated a kind of flexibly monolithic saturable absorber (SA) with GaAs nanowires (NWs) on polyimide (PI) plastic substrate for broadband optical modulation at 1.0 and 1.5 µm, separately. The monolithic SA sample was prepared by the metalorganic vapor phase epitaxy (MOVPE) method. The crystal structure and element analysis were examined carefully by high-resolution scanning transmission electron microscopy (HRSTEM) and energy-dispersive X-ray spectroscopy (EDX). We observed a high-density distribution of NWs on the flexible substrate by scanning electron microscopy (SEM). In addition, linear and nonlinear optical properties of the sample were examined by testing the photoluminescence and absorption properties, which showed its potential application as an optical switch due to the pure semiconducting properties. After the characterizations, we experimentally demonstrated this monolithic SA for laser modulation at 1.0 and 1.5 µm, which yielded the minimum optical pulse widths of 1.531 and 6.232 µs, respectively. Our work demonstrated such a kind of monolithic flexible NW substrate-integrated device used for broadband optical modulation, which not only eased the integration process of NWs onto the fiber endface, but also proved the potential of easily integrating with more semiconducting nanomaterials (e.g., graphene, MoS2, …) to realize monolithic active flexible photonic systems, such as a microscale phase modulator, delay-line, and so on, paving an easy avenue for the development of both active and flexible photonic devices.
Funding Information: H.Y. acknowledges funding support from the Fundamental Research Funds for the Central Universities (grants No.: 501QBJH2023117011), and the National Natural Science Foundation of China (grants No.: 502TSXK2023117002, 606QNQR2023117003). V.K. acknowledges the support of Aalto University Doctoral School, the WalterAhlström Foundation, Elektroniikkainsinöörien Säätiö, Sähköinsinööriliiton Säätiö, the Nokia Foundation, the Finnish Foundation for Technology Promotion (Tekniikan Edistämissäätiö), Kansallis-Osake-Pankki, Waldemar von Frenckell’s foundation and the Emil Aaltonen Foundation. We acknowledge the provision of facilities and technical support by the Aalto University at Micronova Nanofabrication Centre. Publisher Copyright: © 2023 by the authors.
flexible photonics, GaAs nanowires, nonlinear optical modulation, saturable absorber
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Zhao , Y , Yang , H , Khayrudinov , V , Lipsanen , H , Su , X , Qi , M , Lu , B & Song , N 2023 , ' Monolithic Saturable Absorber with Gallium Arsenide Nanowires Integrated on the Flexible Substrate for Optical Pulse Generation ' , Micromachines , vol. 14 , no. 9 , 1702 .