LED準直光源模組於吸收光檢測之應用

A Collimated LED Light Module for Absorbance Detection

翁俊仁(Chun-Jen Weng) ； 謝哲偉(Jer-Wei Hsieh) ； 黃宏琳(Hung-Lin Huang) ； 許俸昌(Feng-Chang Hsu) ； 林明瑜(Ming-Yu Lin)

《科儀新知》 148期 (2005/10) Pp. 36-45

https://doi.org/10.29662/IT.200510.0005

摘要

在吸收光檢測系統中，靈敏度和光源之準直特性有直接的關係。本研究旨在開發低成本、小型化、多通道準直光源模組，一般市售LED雖具有低成本、微型化等特點，但其發散角皆大於10度，且光束分布亦不均勻，不宜直接用於生醫晶片作為吸收光檢測光源之用。本研究提出利用光纖準直器低發散角的特性將LED準直，在1.5公分光程距離裡，發散角僅約1.2度左右。本小型準直光源模組可同時有5通道之輸出，輸出功率變化一小時內低於1%。實際應用於肝功能吸收光檢測上，標準試劑丙酮酸鈉濃度範圍從0-82μM，所測得靈敏度為7.7×10^3/M，其線性度可達R^2=0.9995。

並列摘要

In the bio absorbance detection systems, sensitivity of detection depends on collimation length of light module. Although the conventional LEDs have the advantages of low cost and compact, their light is diverged with divergence angle larger than 10 degree. Therefore, conventional LEDs are not suitable for bio-chip absorbance detection. By exploiting the concept of fiber collimator, this project proposes a design to realize a collimated light module. The advantages of low cost, miniaturized, and multi-channel capability are then achieved. The divergence angle of this collimator is about 1.2 degree within 1.5 cm optical path length. The power variation of this module is under 1% within an hour. The absorbance experiment to measure sodium pyruvate range from 0 to 82 μM using fabricated light module was conducted, where sensitivity of 7.7×10^3/M and linearity of 0.9995 R^2 is obtained.