Research On The Integrated Photonic Crystal Filter And Micro Liquid/Liquid Waveguide Device

Integrated photonic device is an important part of photonics circuits. 'Integrated photonics' means several photonic components fabricated and integrated on a planar substrate. These components include beam splitters, gratings, couplers, polarisers, interferometers, sources and detectors, and others. In turn, these can then be used as buiding blocks to fabricate more complex planar devices which can perform a wide range of functions with applications in optical communication systems and sensors.The advantanges of the photonic device are the high speed, large capacity, low loss and so on because the propogation media is photonics. In this thesis two integrated device is discussed, photonic crystal filter and micro liquid/liquid waveguide.This thesis presents the theoretical model of the side-coupled photonic crystal filter and the gratings. Numerical verification shows a good agreement between the theoretic method and the finite-difference time-domain simulation, but the theoretic method does not involve the time-consuming computation. The theoretical method also presents a better physical image for choosing the critical parameters. Based on the theoretic model, two optimization methods (chirp and cascading) are proposed to deeply suppress the sidelobes, the sidelobe surpression ratio is 30dB. They also show more flexibility in controlling the bandwidth and steepness of the roll-off in the filter. Comparing to apodized technique, it is easy to fabricate.The potential applications of the micro integrated photonic devices and microfluidic systems are mainly twofold. In the context of integrated biochemical sensing, fluids can be used to carry substances to be analysed through highly sensitive microphotonic circuits. Conversely, microfluids can be exploited to control microphotonic devices, making them tunable, reconfigurable and adaptive. In the thesis the optical properties such as the propogation and the loss of the liquid/liquid waveguide were measured and discussed. Two liquid/liquid waveguide sensors were proposed, transmission sensor and absorption sensor. The size of the transmission sensor is 3cm×3cm. The sensitivity is△S/△C=275μm~2 L/mol. The size of the absorption sensor is 3.5cm×3cm. The limitation of detection is 0.5 ng/mL for rhodamin 6G and 0.16 ng/mL for Mathylene blue. Campared with the solid/liquid sensor the liquid/liquid senor has the advantage of flexible and easy for use. The liquid sensor has small size when its sensitivity is the same as the solid/liquid sensor. The two sensos have the same structure. The transmision sensor can be used for the high concentration sample detection and the absorption can be used for the low concentration. It is impossible for traditional solid/liquid waveguide senor to use the same circiut to satisfy the different needs. The twin Mach-Zenhder interferometer based on the liquid/liquid waveguide can be used to detect the position of the paticles for the particles sorting. This particle sorting device is high sensitivity.