Design and fabrication of tapered microfiber waveguide with good optical and mechanical performance

• Published in: Journal of modern optics Vol. 61; no. 8; pp. 683 - 687
• Main Authors: Ma, Cheng-Ju, Ren, Li-Yong, Xu, Yi-Ping, Wang, Ying-Li, Liang, Jian, Qu, En-Shi
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 04.05.2014; Taylor & Francis Ltd
• Subjects: Analysis; contour profile; Decay; Design; Design engineering; evanescent field; Experiments; Fibers; Microfibers; Noise levels; Optics; Optimization; Surface roughness; tapered microfiber waveguide; Waveguides; Wavelengths
• ISSN: 0950-0340; 1362-3044
• DOI: 10.1080/09500340.2014.909541

In this paper, the inherent dependence of optical and mechanical characteristics of tapered microfiber waveguide on its contour profile is studied. Both theoretical analysis and experimental investigation are given. In theory, the optimal profile parameters of the tapered microfiber are proposed to improve the microfiber performance, where it is better to make the tapered microfiber keep two longer than 5-mm-long transition regions which have a decaying exponential profile. And the uniform waist diameter of the tapered microfiber should be more than 600 nm and less than 1 μm. In this case, the microfiber indicates several favorable advantages, such as low loss, strong evanescent field and relatively shorter transition region. In experiment, according to the profile parameters we proposed, we successfully fabricated a tapered microfiber with a low loss of 0.05 dB in air and 0.8 dB on a MgF 2 substrate at the wavelength of 1550 nm, and it has low surface roughness.