Baptista M S, Tran C D
Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201-2270, USA.
Appl Opt. 1997 Sep 20;36(27):7059-65. doi: 10.1364/ao.36.007059.
A novel spectrometer that is based on the use of the thermal lens effect for sensitive measurements of absorption in the near-IR region has been developed. In this instrument the near-IR excitation light (from 1515 to 1590 nm) was provided by an erbium-doped fiber amplifier (EDFA). An acousto-optic tunable filter (AOTF) was used to spectrally disperse the light from the EDFA. The AOTF was used in a new configuration in which, instead of the diffracted light, the transmitted light was used. The heat generated as a consequence of the absorption of the near-IR excitation beam by the sample was monitored by a He-Ne laser. The sensitivity of this spectrometer was found to be at least two to three times higher than that of conventional transmission measurements. Its application in the sensitive determination of nucleotides (adenosine, cytidine, guanosine, and thymidine) is described.
一种基于利用热透镜效应在近红外区域进行吸收灵敏测量的新型光谱仪已被研制出来。在该仪器中，近红外激发光（波长范围为1515至1590纳米）由掺铒光纤放大器（EDFA）提供。使用了一个声光可调滤波器（AOTF）对来自EDFA的光进行光谱色散。AOTF采用了一种新的配置，即使用透射光而非衍射光。通过氦氖激光器监测样品吸收近红外激发光束所产生的热量。结果发现，该光谱仪的灵敏度至少比传统透射测量高两到三倍。文中描述了其在灵敏测定核苷酸（腺苷、胞苷、鸟苷和胸苷）方面的应用。
