表面等离子共振双光束差分研究和数值模拟

为提高光强调制型表面等离子共振传感器的灵敏度和抗干扰能力,本文提出了一种采用双光束差分光强的SPR检测新方法.通过对该方法的理论计算和数值模拟分析,得到了不同入射角和不同金膜厚度时,反射光强差与样品折射率之间的关系曲线.研究表明,与传统的光强调制方法相比,当两束光入射角相差5°,金膜厚度在40～50 nm时,该方法是有更高的灵敏度和更宽的测量范围,并且由于采用了光强差分技术,大大提高了传感器的抗干扰性和稳定性.

Study and numerical simulation of a surface plasmon resonance sensor using bi-beam differential measurement approach

In this article, a novel measurement approach of Surface Plasmon Resonance (SPR) with bi-beam was presented in order to improve the sensitivity and anti-disturbance capability of intensity-modulated SPR sensor. The relation curves between reflected light intensity and sample refractive index were established at different incident angles and gold film thickness, based on theoretical calculation and numerical simulation of this new method. Compared with the traditional intensity-modulated technology, studies indicates that bi-beam approach has better sensitivity and broader measuring range when the incident angle difference of the two beams is equal to 5 degree and gold film thickness is in the range of 40 to 50 nm. The noiseproof feature and stability of the sensor system are greatly improved with the application of light intensity difference technology.