An In-Fiber Coupler for Whispering-Gallery-Mode Excitation in a Microsphere Resonator

An integrated in-fiber coupler for excitation of whispering-gallery modes (WGMs) of a microsphere resonator is proposed. The device is fabricated by embedding a microsphere into an optical fiber inner air-cavity through an open micro-channel to excite various WGMs via evanescent field coupling. The asymmetric Fano resonance line shape and the symmetrical Lorentzian line shape with a slope of −13.88 dB/nm and a quality (Q)-factor of <inline-formula> <tex-math notation="LaTeX">$1.81\times 10^{3}$ </tex-math></inline-formula> are observed in the transmission spectrum of the device. Such an in-fiber WGM resonator coupling structure has the features of compactness, low-cost, robust and alignment-free.

[1]  Libo Yuan,et al.  Embedded whispering-gallery mode microsphere resonator in a tapered hollow annular core fiber , 2018, Photonics Research.

[2]  Tingyun Wang,et al.  Theoretical aspects and sensing demonstrations of cone-shaped inwall capillary-based microsphere resonators , 2017 .

[3]  Xiang Yin,et al.  Dynamically Tunable Electromagnetically Induced Transparency in Graphene-Based Coupled Micro-ring Resonators , 2017, IEEE Photonics Journal.

[4]  F. Pang,et al.  Fano resonances in cone-shaped inwall capillary based microsphere resonator. , 2017, Optics express.

[5]  T. Zhu,et al.  Thermo–Optic Tuning of Integrated Polymethyl Methacrylate Sphere Whispering Gallery Mode Resonator , 2016, IEEE Photonics Journal.

[6]  Keyi Wang,et al.  Package of a dual-tapered-fiber coupled microsphere resonator with high Q factor , 2015 .

[7]  Matthew R Foreman,et al.  Whispering gallery mode sensors. , 2015, Advances in optics and photonics.

[8]  X. Qiao,et al.  Integrated in-fiber coupler for microsphere whispering-gallery modes resonator excitation. , 2015, Optics letters.

[9]  Franco Nori,et al.  What is and what is not electromagnetically induced transparency in whispering-gallery microcavities , 2014, Nature Communications.

[10]  Feng Luan,et al.  Fano resonances in metallic grating coupled whispering gallery mode resonator , 2013 .

[11]  C. Liao,et al.  Miniaturized fiber in-line Mach-Zehnder interferometer based on inner air cavity for high-temperature sensing. , 2012, Optics letters.

[12]  Yan Li,et al.  Experimental controlling of Fano resonance in indirectly coupled whispering-gallery microresonators , 2012 .

[13]  Yuri S. Kivshar,et al.  Fano Resonances in Nanoscale Structures , 2010 .

[14]  J. Ward,et al.  A Taper-Fused Microspherical Laser Source , 2008, IEEE Photonics Technology Letters.

[15]  Amnon Yariv,et al.  Transmission characteristics of a Fabry-Perot etalon-microtoroid resonator coupled system. , 2006, Optics letters.

[16]  A. Matsko,et al.  Optical resonators with whispering-gallery modes-part II: applications , 2006, IEEE Journal of Selected Topics in Quantum Electronics.

[17]  A. Matsko,et al.  Optical resonators with whispering-gallery modes-part I: basics , 2006, IEEE Journal of Selected Topics in Quantum Electronics.

[18]  Shanhui Fan,et al.  Sharp asymmetric line shapes in side-coupled waveguide-cavity systems , 2002 .

[19]  T. Zhu,et al.  In-fiber Mach-Zehnder interferometer and sphere whispering gallery mode resonator coupling structure. , 2017, Optics letters.

[20]  Y. Kivshar,et al.  Fano resonance in nanoscale structures , 2009 .

[21]  A. Poon,et al.  Fano resonances in prism-coupled square micropillars. , 2004, Optics letters.