Aq6373b

The spectral characterization of the metadevice was made based on a measuring system that was built on the basis of the supercontinuum laser SC450-4-AOTF (Fianium, NKT Photonics) and optical spectrum analyzer AQ6373B (Yokogawa) with wavelength accuracy of ± 0.05 nm. Light from a supercontinuum source was coupled to a standard telecommunication single-mode fiber SMF28 (Corning) to illuminate a metamaterial cell. Also, the same kind of a fiber was used for providing a signal to the optical spectrum analyzer. The SMF28 series has a core diameter equal to 8 µm and a numerical aperture NA = 0.14. To ensure precise manipulation of the fiber position in relation to the DFLC-loaded metamaterial cell, the 3DMAX system with piezomechanical controls from Thorlabs was used. The measurement system also included the waveform generator DG1022 (Rigol) and the linear voltage amplifier F10AD (FLC Electronics).

In this research, influence of the metallic layer deposited on the optical fiber taper on the light propagation in the LC cell was under investigation. To achieve spectral characteristics, the measurement system was built of a broad-spectrum light source-SuperK EXTREME supercontinuum (SC), from NKT Photonics (Birkerød, Denmark), and Optical Spectrum Analyzer (OSA) Yokogawa AQ6373B (Japan, Tokyo) with the ability to provide short time and accurate analysis of the short wavelength range between 350 and 1200 nm used for the light analysis. Electric signal necessary to the steering LC cell was generated by the function generator RIGOL DG1022Z (Beijing, China). The spectral analysis was conducted at room temperature for cells with three various molecules orientations and with and without 30 nm gold layer. In order to investigate the differences between cells, the measurements were performed under the various voltage U in the range of 0–200 V, without modulation of an output signal and with an amplitude modulation (AM) with frequency f equal to 5 Hz and a 100% depth. Figure 5 presents the used measuring system.