title: Reconfigurable Liquid Whispering Gallery Mode Microlasers.
abstract: Engineering photonic devices from liquid has been emerging as a fascinating research avenue. Reconfigurably tuning liquid optical micro-devices are highly desirable but remain extremely challenging because of the fluidic nature. In this article we demonstrate an all-liquid tunable whispering gallery mode microlaser floating on a liquid surface fabricated by using inkjet print technique. We show that the cavity resonance of such liquid lasers could be reconfigurably manipulated by surface tension alteration originated from the tiny concentration change of the surfactant in the supporting liquid. As such, remarkable sensing of water-soluble organic compounds with a sensitivity of free spectral range as high as 19.85 THz / (mol · mL(-1)) and the detectivity limit around 5.56 × 10(-3) mol · mL(-1) is achieved. Our work provides not only a novel approach to effectively tuning a laser resonator but also new insight into potential applications in biological, chemical and environmental sensing.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link, 637371, Singapore.
authors.forename: Shancheng
authors.initials: S
authors.lastname: Yang
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link, 637371, Singapore.|Department of Physics, King's College London, Strand, London, WC2R 2LS, UK.
authors.forename: Van Duong
authors.initials: VD
authors.lastname: Ta
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link, 637371, Singapore.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link, 637371, Singapore.|Department of Electrical and Electronic Engineering, South University of Science and Technology of China, Shenzhen, Guangdong, 518055, P. R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Chen
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link, 637371, Singapore.|College of Physics Science &Technology, Shenzhen University, Shenzhen, Guangdong, 518060, P. R. China.
authors.forename: Tingchao
authors.initials: T
authors.lastname: He
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link, 637371, Singapore.|Centre for Disruptive Photonic Technologies (CDPT), Nanyang Technological University, Nanyang Link, 637371, Singapore.|School of Electrical and Electronic Engineering, Luminous! Center of Excellence for Semiconductor Lighting and Displays, Nanyang Technological University, Nanyang Avenue, 639798, Singapore.|Department of Electrical and Electronics Engineering, Department of Physics and UNAM-National Nanotechnology Research Center, Bilkent University, Bilkent, 06800 Ankara, Turkey.
authors.forename: Hilmi Volkan
authors.initials: HV
authors.lastname: Demir
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link, 637371, Singapore.|Centre for Disruptive Photonic Technologies (CDPT), Nanyang Technological University, Nanyang Link, 637371, Singapore.
authors.forename: Handong
authors.initials: H
authors.lastname: Sun