费米折射率平面波导激励的差分检测型对称结构表面等离子共振传感研究

发布时间：2018-07-27 09:49

【摘要】：为了实现被测折射率范围可调,提高检测灵敏度,将双波长差分检测技术应用于平面波导激励的金属-介质-金属组成的对称型表面等离子体共振传感结构中.通过对对称结构的模式特性分析,研究了该结构中激发等离子体表面波时,介质厚度与被测折射率的关系及双波长差分检测的原理.采用离子交换法制备平面波导,用费米函数拟合其渐变折射率分布.用光强调制方式,分别进行单波长和双波长差分检测,对折射率为1.33~1.428之间的甘油溶液进行测试,实验结果表明,该结构可激发等离子体表面波,与传统平面波导激励的表面等离子体共振传感结构相比,通过改变被测介质的厚度可以改变共振条件,进而改变折射率的测量范围.若被测范围选择合适,检测的线性较好,采用差分检测方法比单波长检测方法的灵敏度提高近一倍.
[Abstract]:In order to realize the adjustable refractive index range and improve the detection sensitivity, the dual wavelength differential detection technique is applied to the symmetrical surface plasmon resonance sensing structure of metal dielectric metal formed by a planar waveguide. By analyzing the mode characteristics of the symmetrical structure, the plasma surface wave excited by the excited plasma is studied. The relationship between the mass thickness and the measured refractive index and the principle of the dual wavelength differential detection. Using the ion exchange method to prepare the planar waveguide and fitting the gradient index distribution with Fermi function. The single wavelength and double wavelength differential detection are carried out with the light intensity modulation method. The glycerol solution between the refractive index of 1.33~1.428 is tested and the experimental result table is tested. Compared with the surface plasmon resonance sensing structure excited by the traditional planar waveguide, the structure can change the resonance condition by changing the thickness of the measured medium, and then change the measurement range of the refractive index. If the range of measurement is suitable, the linearity of the test is better and the difference detection method is compared with the single wavelength. The sensitivity of the detection method is nearly doubled.
【作者单位】：上海理工大学光电信息与计算机工程学院;上海工程技术大学电子电气工程学院;
【基金】：国家自然科学基金(Nos.61302181,61007002) 上海市教委科研创新项目(No.13YZ111) 上海市自然科学基金(No.14ZR1418400)资助
【分类号】：TN814

【共引文献】