Title :
Micro-Displacement Sensor With Large Dynamic Range Based on Photonic Crystal Co-Directional Coupler
Author :
Xu, Zhenfeng ; Cao, Liangcai ; Su, Ping ; He, Qingsheng ; Jin, Guofan ; Gu, Glaire
Author_Institution :
State Key Lab. of Precision Meas. Technol. & Instrum., Tsinghua Univ., Beijing
Abstract :
A novel micro-displacement sensor based on a photonic crystal (PhC) co-directional coupler and its sensing technique are presented. The coupler consists of a fixed and a movable PhC segments. Due to the translational symmetry of the PhC structure, this sensing technique is valid for a large displacement on the order of na (n is an integer, and a is the lattice constant of the PhC). After optimization, the outputs of the sensor are approximately sine functions of the displacement, thus it has the potential to achieve high resolution using a subdivision approach. These two characteristics ensure the large dynamic range of the micro-sensor. The properties of the micro-displacement sensor are analyzed using the coupled-mode theory and simulated using the finite-difference time-domain method
Keywords :
coupled mode analysis; displacement measurement; finite difference time-domain analysis; micro-optomechanical devices; microsensors; optical directional couplers; photonic crystals; coupled-mode theory; finite-difference time-domain method; lattice constant; microdisplacement sensor; photonic crystal codirectional coupler; Atomic force microscopy; Atomic measurements; Dynamic range; Finite difference methods; Helium; Lattices; Optoelectronic and photonic sensors; Photonic crystals; Sensor phenomena and characterization; Time domain analysis; Coupler; micro-displacement sensing; photonic crystals; subdivision;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2006.886449
