The filtering properties of a continuously tunable single-passband microwave photonic filter based on stimulated Brillouin scattering (SBS) are investigated. The filter utilizes the advantage of combining phase-modulated RF signal and dual-sideband suppressed-carrier pump signal to achieve the SBS-based tunable narrowband filtering. The effects of pump power on the out-of-band rejection (OBR) and 3-dB bandwidth, the optical fiber structure on the resonant sideband, and input RF signal power on the OBR and 3-dB bandwidth are analyzed theoretically and experimentally. The results show that the pump power has the potential of increasing the OBR and tuning 3-dB bandwidth, whereas the RF signal power has nearly no influence on the two parameters.
In this article, a kind of microfluidic method based on MEMS technology combined with gold immunochromatographic
assay (GICA) is developed and discussed. Compared to the traditional GICA, this method supplies us convenient,
multi-channel, in-parallel, low cost and similar efficiency approach in the fields of alpha-fetopro-tei (AFP)detection.
Firstly, we improved the adhesion between the model material SU-8 and Silicon wafer, optimized approaches of the
fabrication of the SU-8 model systematically, and fabricate the PDMS micro fluid chip with good reproduction
successfully. Secondly, Surface modification and antibody immobilization methods with the GICA on the PDMS micro
fluid analysis chip are studied, we choose the PDMS material and transfer GICA to the PDMS micro fluid chip
successfully after researching the antibody immobilization efficiency of different materials utilized in fabrication of the
micro fluid chip. In order to improve the reaction efficiency of the immobilized antibody, we studied the characteristics
of micro fluid without the gas drive, and the fluid velocity control in our design; we also design structure of grove to
strengthen the ability of immobilizing the antibody. The stimulation of the structure shows that it achieves great
improvement and experiments prove the design is feasible.