In this paper, we reviewed the design principles of two-dimensional （2D） silicon photonic crystal microcavity （PCM） biosensors coupled to photonie crystal waveguides （PCWs）. Microcavity radiation loss is con- tr...In this paper, we reviewed the design principles of two-dimensional （2D） silicon photonic crystal microcavity （PCM） biosensors coupled to photonie crystal waveguides （PCWs）. Microcavity radiation loss is con- trolled by engineered the cavity mode volume. Coupling loss into the waveguide is controlled by adjusting the position of the microcavity from the waveguide. We also investigated the dependence of analyte overlap integral （also called fill fraction） of the resonant mode as well as the effect of group index of the coupling waveguide at the resonant wavelength of the microcavity. In addition to the cavity properties, absorbance of the sensing medium or analyte together with the affinity constant of the probe and target biomarkers involved in the biochemical reaction also limits the minimum detection limits. We summarized our results in applications in cancer biomarker detection, heavy metal sensing and therapeutic drug monitoring.展开更多
An in-line fiber Fabry-Perot interferometer （FPI） based on the hollow-core photonic crystal fiber （HCPCF） for refractive index （RI） measurement is proposed in this paper. The FPI is formed by splicing both ends ...An in-line fiber Fabry-Perot interferometer （FPI） based on the hollow-core photonic crystal fiber （HCPCF） for refractive index （RI） measurement is proposed in this paper. The FPI is formed by splicing both ends of a short section of the HCPCF to single mode fibers （SMFs） and cleaving the SMF pigtail to a proper length. The RI response of the sensor is analyzed theoretically and demonstrated experimentally. The results show that the FPI sensor has linear response to external RI and good repeatability. The sensitivity calculated from the maximum fringe contrast is -136 dB/RIU. A new spectrum differential integration （SDI） method for signal processing is also presented in this study. In this method, the RI is obtained from the integrated intensity of the absolute difference between the interference spectrum and its smoothed spectrum. The results show that the sensitivity obtained from the integrated intensity is about -1.34× 10^5 dB/RIU. Compared with the maximum fringe contrast method, the new SDI method can provide the higher sensitivity, better linearity, improved reliability, and accuracy, and it＇s also convenient for automatic and fast signal processing in real-time monitoring of RI.展开更多
文摘In this paper, we reviewed the design principles of two-dimensional （2D） silicon photonic crystal microcavity （PCM） biosensors coupled to photonie crystal waveguides （PCWs）. Microcavity radiation loss is con- trolled by engineered the cavity mode volume. Coupling loss into the waveguide is controlled by adjusting the position of the microcavity from the waveguide. We also investigated the dependence of analyte overlap integral （also called fill fraction） of the resonant mode as well as the effect of group index of the coupling waveguide at the resonant wavelength of the microcavity. In addition to the cavity properties, absorbance of the sensing medium or analyte together with the affinity constant of the probe and target biomarkers involved in the biochemical reaction also limits the minimum detection limits. We summarized our results in applications in cancer biomarker detection, heavy metal sensing and therapeutic drug monitoring.
基金This research is supported by the National Natural Science Foundations of China （Grant Nos. 61174018 and 61505097） and Fundamental research funds of Shandong University, China （Grant No.2014YQ009）.
文摘An in-line fiber Fabry-Perot interferometer （FPI） based on the hollow-core photonic crystal fiber （HCPCF） for refractive index （RI） measurement is proposed in this paper. The FPI is formed by splicing both ends of a short section of the HCPCF to single mode fibers （SMFs） and cleaving the SMF pigtail to a proper length. The RI response of the sensor is analyzed theoretically and demonstrated experimentally. The results show that the FPI sensor has linear response to external RI and good repeatability. The sensitivity calculated from the maximum fringe contrast is -136 dB/RIU. A new spectrum differential integration （SDI） method for signal processing is also presented in this study. In this method, the RI is obtained from the integrated intensity of the absolute difference between the interference spectrum and its smoothed spectrum. The results show that the sensitivity obtained from the integrated intensity is about -1.34× 10^5 dB/RIU. Compared with the maximum fringe contrast method, the new SDI method can provide the higher sensitivity, better linearity, improved reliability, and accuracy, and it＇s also convenient for automatic and fast signal processing in real-time monitoring of RI.
