Two-photon excited fluorescence from a pseudoisocyanine-attached gold-coated tip via a thin tapered fiber under a weak continuous wave excitation

Abstract

A simple tapered fiber based photonic-plasmonic hybrid nanostructure composed of a thin tapered fiber and a pseudoisocyanine (PIC)-attached Au-coated tip was demonstrated. Using this simple hybrid nanostructure, we succeeded in observing two-photon excited fluorescence from the PIC dye molecules under a weak continuous wave excitation condition. From the results of the tip-fiber distance dependence and excitation polarization dependence, we found that using a thin tapered fiber and an Au-coated tip realized efficient coupling of the incident light (~95%) and LSP excitation at the Au-coated tip, suggesting the possibility of efficiently inducing two-photon excited fluorescence from the PIC dye molecules attached on the Au-coated tip. This simple photonic-plasmonic hybrid system is one of the promising tools for single photon sources, highly efficient plasmonic sensors, and integrated nonlinear plasmonic devices. 5263-5276 (1997). 36. A. Hartung, S. Brueckner, and H. Bartelt, "Limits of light guidance in optical nanofibers," Opt. Express 18(4), 3754-3761 (2010). 37. M. Fujiwara, K. Toubaru, and S. Takeuchi, "Optical transmittance degradation in tapered fibers," Opt. Express 19(9), 8596-8601 (2011). 38. H. Konishi, H. Fujiwara, S. Takeuchi, and K. Sasaki, "Polarization-discriminated spectra of a fiber-microsphere system," Appl. Phys. Lett. 89(12), 121107 (2006).

Detailed Observation of Multiphoton Emission Enhancement from a Single Colloidal Quantum Dot Using a Silver-Coated AFM Tip

“…The AgTip was prepared by sputtering Ag onto a silicon AFM cantilever with a 7 nm tip radius (Olympus, OMCL-AC160TS-R3). The scattering spectrum of the AgTip was measured by contacting the AgTip with a taper fiber coupled with a white light source, 48 and numerical simulations of the AgTip were conducted using finite element analysis. Details are provided in the SI.…”

Two-Photon-Excited Emission of Quantum Dots with a Plasmonic Chip

“…In 2016, Ren et al studied a plasmonic hybrid nanostructure composed of a gold-film coating tipped with a tapered fiber and the pseudoisocyanine (PIC) dye, and 2PE from the PIC dye was detected under a continuous wave (CW) laser at a low irradiation intensity (several tens of kW/cm 2 ). 9 Furthermore, in 2016, Jensen et al fabricated a bowtie aperture substrate coated with a thin silver film, and the optical trapping of QDs and 2PE was detected using a CW laser (1.56 MW/cm 2 ). 10 In 2019, Rabor et al reported the detection of 2PE induced by a picosecond-pulse laser from fluorescence molecules, including rhodamine 6G, fixed to a glass slide modified with a triangular silver nanoprism.…”

Non-contact detection of nanoscale structures using optical nanofiber

“…They have also been employed to efficiently couple fluorescence from single-light emitters to single-mode fibers [9][10][11][12][13][14][15][16]. In addition, nanofibers have been used in the generation of supercontinuum [17], two-photon excited fluorescence [18], and more recently in optical tweezers [19].…”

“…We consider that the high sensitivity of the transmission degradation of the nanofiber is useful for detecting material differences and nano-structures on the surface of an object. For example, when a nanofiber is vertically moved towards a point on an object, the change in the transmission depends on the material and the structure at that point [18]. Also, when a nanofiber is horizontally scanned over the surface of an object, the distribution of the material and nano-structure on the object can be detected from the transmission change.…”