Polarization-dependent properties of the cladding modes of a single mode fiber covered with gold nanoparticles

Abstract

The properties of the high order cladding modes of standard optical fibers are measured in real-time during the deposition of gold nanoparticle layers by chemical vapor deposition (CVD). Using a tilted fiber Bragg grating (TFBG), the resonance wavelength and peak-to-peak amplitude of a radially polarized cladding mode resonance located 51 nm away from the core mode reflection resonance shift by 0.17 nm and 13.54 dB respectively during the formation of a ~200 nm thick layer. For the spectrally adjacent azimuthally polarized resonance, the corresponding shifts are 0.45 nm and 16.34 dB. In both cases, the amplitudes of the resonance go through a pronounced minimum of about 5 dB for thickness between 80 and 100 nm and at the same time the wavelengths shift discontinuously. These effects are discussed in terms of the evolving metallic boundary conditions perceived by the cladding modes as the nanoparticles grow. Scanning Electron Micrographs and observations of cladding mode light scattering by nanoparticle layers of various thicknesses reveal a strong correlation between the TFBG polarized transmission spectra, the grain size and fill factor of the nanoparticles, and the scattering efficiency. This allows the preparation of gold nanoparticle layers that strongly discriminate between radially and azimuthally polarized cladding mode evanescent fields, with important consequences in the plasmonic properties of these layers.

Surfactant Directed Growth of Gold Metal Nanoplates by Chemical Vapor Deposition

“…51 Single-source, hot-walled CVD experiments were performed using 1 and 2 over a substrate temperature range of 150 -500 ºC using Si [100] substrates on a home-built apparatus. 52 Both precursors produced nanoparticulate films (these included decahedrons, triangles and octahedrons as well as amorphous particles) starting at 300 °C. Pentagonal wires with nanoscale cross-sections were observed sparsely in all depositions, and there was no apparent trend to their growth ( Figure 3).…”

“…Experiments were performed on a home-built, low-pressure, hot-walled CVD apparatus. 52 Precursor masses of 50 to 310 mg were delivered from an open-ended vial placed on its side. In the case of 2, a valve was placed between the precursor vial and the furnace which allowed the precursor vial to be loaded in a glovebox and remain air-free during system assembly.…”

Intensity-modulated magnetic field sensor based on magnetic fluid and optical fiber gratings

“…It was reported that absorption and scattering of metal nanoparticles can change transmission spectrum of TFBG by introducing additional losses. 18,19 The Fe 3 O 4 nanoparticles and the magnetic chains/columns formed under magnetic field make the cladding modes of the TFBG lossy through evanescent field. 12 The so-caused loss or attenuation can be described with imaginary part of complex refractive index of the MF.…”

Light Polarization-Assisted Sensing with Tilted Fiber Bragg Gratings

“…Very recently, gold nanoparticles have been deposited on TFBGs using chemical vapor deposition (CVD) process [34]. Again, a differential behavior was reported between Pand S-polarized lightwaves, the former being the most attenuated in the amplitude spectrum due to an important scattering by the metal nanoparticles.…”