The Measurement Of The Refractive Index Of Bio-tissues Based On Spectral Domain-optical Coherence Reflectometric

The refractive index of biological tissue is its important optical properties. Since the1990’sscientists initially established a light in biological tissue of the spread of the mathematical model, toprovide the theoretical basis of research for later generations, but the theory has not been perfected yet.The research of the optical properties of biological tissue, including the refractive index measurementmethod and technology is developing. In recent years, the optical fiber bio-sensing technology offersa new way for its measurement.This paper firstly expounds the meaning of biological tissue refractive index, and then throughthe introduction of the development and insufficient of the biological tissue refractive indexmeasuring technique and Optical low coherent interference technology at home and abroad, putforward biological tissues refractive index measuring technique based on the Spectral Domain-OpticalCoherence Reflectometric(SD-OCR)method. Common-path method was used to simplify thesystem structure, improve the measuring speed and has a strong anti-disturbance ability. Broadbandlight (center wavelength850nm, half peak bandwidth23.5nm) was transmitted through the Y-couplerand scattered (reflected) back to the spectrum analyzing system(the blazed grating as the core spectralcomponents and，the linear CCD camera as the photoelectric detector) by the specimen through thesample arm and the Y-coupler. use the A/D converter in the camera and USB interface construct ofvirtual instrument system with PC, program data acquisition, signal processing applications based onLabVIEW software, realize the continuous data acquisition, CCD unit-wavelength conversion, fastFourier transform (FFT) and wave peak detection, completed the construction and optimization of themeasurement system.Through the experiments prove the system complies with the requirements. Firstly use standardK9glass plate as samples for verification experiment, prove the system accuracy reached10-3, and theerror is0.29%. Then make the slice of cucumber superficial tissue samples and the refractive index ofa cucumber superficial slice at850nm are measured with the measuring time was less than1minute.Finally, the feasibility of the system technology used to measuring refractive index non-uniform tissuesample is discussed.