Surface Bio-Sensor Based On Terahertz Bragg Fiber

Hollow-core photonic Bragg fibers have a wide range of sensing applications. In this paper, a hollow-core photonic Bragg fiber with a defect layer for surface bio-sensing is proposed and analyzed for bacterium detection in the terahertz (THz) frequency range. The hollow core is surrounded by a periodic sequence of high/low refractive index multilayers including the photosensitive resin and air. The analytes are deposited on the inner surface of the hollow-core THz Bragg fiber. The performance of the proposed sensor is numerically investigated. The result shows that the proposed surface bio-sensor provides a high core power fraction. The confinement loss of the sensor takes on two peaks in the frequency range of 0.3-0.4 and 0.45-0.55 THz, respectively. The distinguishable characteristic frequencies of the sensor are obtained with different bacterium deposited on the inner surface of the THz Bragg fiber. Furthermore, the thickness-independent surface sensing can be realized in the high frequency range. The proposed surface bio-sensor based on THz Bragg fiber can be used to recognize the kind of the bacterium and has a great potential in microorganism detections.