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• Chinese Optics Letters
• Vol. 21, Issue 1, 011101 (2023)
Feifei Qin, Fan Shi, Xumin Gao, Jiabin Yan, Ziqi Ye, Yulong Su, Jianwei Fu, and Yongjin Wang*
Author Affiliations
• Grünberg Research Centre, College of Telecommunications and Information Engineering, , Nanjing 210003, China
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Feifei Qin, Fan Shi, Xumin Gao, Jiabin Yan, Ziqi Ye, Yulong Su, Jianwei Fu, Yongjin Wang. Self-filtering illumination source and application in fluorescence imaging[J]. Chinese Optics Letters, 2023, 21(1): 011101 Copy Citation Text show less

Abstract

To date, fluorescence imaging systems have all relied on at least one beam splitter (BS) to ensure the separation of excitation light and fluorescence. Here, we reported $SiO2/TiO2$ multi-layer long pass filter integrated GaN LED. It is considered as the potential source for imaging systems. Experimental results indicate that the GaN LED shows blue emission peaked at 470.3 nm and can be used to excite dye materials. Integrating with a long pass filter (550 nm), the light source can be used to establish a real-time fluorescence detection for dyes that emit light above 550 nm. More interestingly, with this source, a real-time imaging system with signature words written with the dyes, such as ‘N J U P T’, can be converted into CCD images. This work may lead to a new strategy for integrating light sources and BS mirrors to build mini and smart fluorescence imaging systems.

1. Introduction

Fluorescence detection is a non-contact and non-destructive probing technique, which has achieved great attention due to its effectiveness and specificity[13]. Compared with traditional laser sources, light emitting diodes (LEDs) provide a cheaper light source and are easy-to-use in fluorescence detection systems[46]. Optical systems for the detection of fluorescent signals or fluorescence imaging are typically composed of a light source for emitting light at the dye absorption band, a filter for removing the unwanted excitation light at the receiving end, and a detector or CCD camera for receiving the fluorescence signal. Commonly, the optical systems are bulky and complicated due to a series of discrete free-space optical elements. Driven by the concept of “lab-on-chip” (LOC), many efforts have been paid to enhance the system integration[711]. For example, Novak et al. reported a miniaturized fluorescence detection system ($30 mm×30 mm×11 mm$) by implementing LOC devices in a metal housing and achieved it[12]. Xue et al. presented a miniaturized fluorescence detection device by mounting an LED and a minor filter into a polydimethylsiloxane (PDMS)-based microchip[13]. This device can be further integrated into a smaller size of $20 mm×20 mm×20 mm$ by integrating all necessary optical components into a metal package[14]. Although the above work has realized the miniaturization of the detection system in the physical dimension, the components of each part are still discretely packaged, and the optical path is still divided into two paths: excitation and detection. If one can realize the coaxial transmission optical path, then the traditional system layout would be significantly simplified, leading to more miniaturized fluorescence detection or imaging devices.

Feifei Qin, Fan Shi, Xumin Gao, Jiabin Yan, Ziqi Ye, Yulong Su, Jianwei Fu, Yongjin Wang. Self-filtering illumination source and application in fluorescence imaging[J]. Chinese Optics Letters, 2023, 21(1): 011101