Optical Microfiber Coupler Decorated by Erbium-Ytterbium Co-Doped Silica Film for Photothermal Optical Modulation and Multifunctional Sensing

• Published in: IEEE sensors journal 2024-11, Vol.24 (21), p.34432-34439
• Main Authors: Zhu, Wanlai, Zhou, Guorui, Yi, Zao, You, Hui, Wang, Dongying, Zeng, Qingdong, Yao, Caizhen, Miao, Xinxiang
• Format: Article
• Language: English
• Subjects: Air flow; Couplers; Decoration; Erbium; Erbium-ytterbium co-doped silica film; Freeports; High temperature; Light modulation; Microfibers; multifunctional sensing; Optical fiber couplers; Optical fiber sensors; Optical fibers; Optical films; optical microfiber coupler (OMC); Optical modulation; Optical properties; photothermal effect; Polydimethylsiloxane; Sensitivity; Sensors; Silicon dioxide; Water tanks; Ytterbium
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2024.3434468

Currently, there are few reports of optic fiber devices that combine efficient photothermal optical modulation and multifunctional sensing in one device. We reported an optical microfiber coupler (OMC) decorated by erbium-ytterbium co-doped silica film with significant photothermal effect, which can be used in the field of optical modulation and multifunctional sensing. It is experimentally verified that a 980-nm laser driven by the current of 500 mA enables the temperature of the decorated OMC waist region up to 82.5~^{\circ } C, and it reveals extreme layer stability, remarkable adsorption properties, and excellent thermo-desorption effects of the device. The OMC encapsulated with polydimethylsiloxane (PDMS) has a temperature sensitivity of up to 1106.88 pm/°C in the temperature range of 28~^{\circ } C- 48~^{\circ } C. And achieved a maximum air-flow sensitivity of 529.39 nm \cdot s/m within the speed range of 0-18.2 m/s using hot-wire-based method. The device is placed in a 20~^{\circ } C water tank to achieve a modulation sensitivity of 24.47 pm/mA with a maximum modulation depth of 16.7 dB, effectively addressing both the response delay and high-temperature hazard caused by thermal accumulation. The device's compact structure, low cost, high sensitivity, and multifunctional applications make it a promising application in the field of multifunctional integration.