The Principle Of Strian Senser Based On Aperiodic Photonic Crystal With Super Narrow Band

Photonic crystals are periodic structures that are designed to affect the motion of photonsin a similar way that periodicity of a semiconductor crystal affects the motion of electrons.The non-existence of propagating EM modes inside the structures at certain frequenciesintroduces unique optical phenomena such as low-loss-waveguides, omni-directional mirrorsand others. The part of the spectrum for which wave propagation is not possible is called theoptical-band gap. Therefore, the lattice constant of the photonic crystal structure has to be inthe same length-scale as half the wavelength of the electromagnetic wave. According to TDWand LPX study, their letter gives a report of a meso-piezoresistive effect in a double-barrierresonant tunneling DBRT structure. In a DBRT system, an external mechanical stress causes atensile strain, and the strain affects the resonant tunneling and thereby the resistance in turn.Theoretical analysis was carried out on an AlAs/GaAs/AlAs DBRT structure under in-planeuniaxial tensile stresses. The study puts emphasis on the relationship between the strain andequivalent resistance. Enlightenment from Meso-piezoresistive effect, an external mechanicalstess causes strain,and the strain,in turn,changes the structure of photonic crystal, whichsimultaneously occurred in band gap of photonic crystals. The main work and achievementsinclude the following aspects:The first chapter gives a comprehensive introduction to the history of development andthe characteristics of photonic crystals (PCs).The second chapter describes the research method of theory of the photonic crystals(PCs) and introduces the transfer matrix method,the finite difference time domain algorithmand so on.The third chapter focuses on photonic band gap (PBG) of a one-dimensional (1-D) photonic crystals (PCs) with aperiodic structures which have been disrupted by a certainrule. Theoretical analysis is carried out on one-dimensional (1-D) photonic crystals (PCs),then narrow transmission peaks appear in many photonic band gaps (PBGs).The fourth chapter mainly reports one-dimensional aperiodic photonic crystal with supernarrow band in this paper. Constrasting one-dimensional periodic photonic crystals (PCs), wecan design a structure of (A·B)~N·(B·A)~Nin one-dimensional PCs, where A and B stand fordifferent dielectric materials, and N=10. The narrow band of transmission peak, which isdefined as super narrow band and obtained the band of0.1nm by us, appears within the1500nm in the forbidden gap of this PCs. The results show that the wavelength of thetransmission peak in the forbidden gap of this PCs is very sensitive to a small strain, where alinear relationship between changed wavelength of transmission peak and different strain wasfound by us. We obtained μ=-1540nm, where meso-piezoptic coefficient μ was introduced toquantify meso-piezoptic effects.In summary, the paper studies the linear relationship between the strain and changedwavelength of super narrow band of transmission peak in photonic band gap (PBG) ofone-dimensional (1-D) photonic crystals (PCs), which is so-called mesoscopic piezophotoniceffect.