液芯光纤预共振和共振喇曼光谱及其应用

Liquid Core Optical Fiber Preresonance and Resonance Raman Spectroscopy and Its Application

在液芯光纤内产生预共振和共振喇曼效应，可大幅度提高喇曼光谱强度。用波长远离样品吸收峰的激光激发观察到了α－甲基吡啶的预共振喇曼光谱。用长１．１ｍ、内径２００μｍ的液芯光纤，波长５１４．５ｎｍ、功率０．８０Ｗ激光激发获得了β－胡罗卜素在ＣＳ２中的共振喇曼光谱，其浓度为２×１０－８ｍｏｌ／Ｌ，比普通方法的样品的浓度低２～３个数量级。光纤共振喇曼技术为应用光纤检测不透明（有吸收）分子提供了一种实验方法。

The spectral intensity may be enhanced greatly by producing preresonance and resonance Raman effects in liquid core optical fiber. Preresonance Raman phenomenon of α- picolines is observed in optical fiber (3. 35 m, 100 μm I. D) using laser wave length 515. 5 nm, 488. 0 nm or 454. 5 nm. The resonance Raman spectrum of β-carotene in CS2 is obtained in optical fiber with 0. 80 mW laser at 514. 5 nm. The concentration is 2 ×10-8 mol/L which is 2-3 orders of magnitude lower than that used in conventional methods. The methods of optical fiber resonance Raman spectroscopy expand the range of application of liquid core optical fiber for measurement of opaque (absorbent) samples.