Demonstrating a Filter-Free Wavelength Sensor with Double-Well Structure and Its Application

Abstract

This study proposed a filter-free wavelength sensor with a double-well structure for detecting fluorescence without an optical filter. The impurity concentration was optimized and simulated to form a double-well-structured sensor, of which the result was consistent with the fabricated sensor. Furthermore, we proposed a novel wavelength detection method using the current ratio based on the silicon absorption coefficient. The results showed that the proposed method successfully detected single wavelengths in the 460–800 nm range. Additionally, we confirmed that quantification was possible using the current ratio of the sensor for a relatively wide band wavelength, such as fluorescence. Finally, the fluorescence that was emitted from the reagents ALEXA488, 594, and 680 was successfully identified and quantified. The proposed sensor can detect wavelengths without optical filters, which can be used in various applications in the biofield, such as POCT as a miniaturized wavelength detection sensor.

(Invited) Detection of Wavelength Information by Filter-Free Wavelength Sensor and Its Applications

“…We applied a filter-free wavelength sensor to microflow cytometry to detect fluorescent beads having different wavelengths. In addition, we succeeded in quantification by detecting the fluorescence of various fluorescent reagents and identifying fluorescence emitted from Legionella bacteria (10,11). Figure 3(b) shows a schematic diagram that can identify the change in the spectrum using a sensor.…”

“…Focusing on the fluorescence intensity of Legionella dumoffii, which emits blue fluorescence, and Legionella erythra, which emits red fluorescence, we proposed a method for identifying Legionella using a filter-free wavelength detection sensor. Figure 5(a) shows the structure and image of the Legionella species identification system (11). Since the wavelength of autofluorescence emitted by each Legionella species differs, it is possible to distinguish them from the current ratio of the filter-free wavelength sensor.…”

Wireless wavelength measurement system with temperature compensation using filter-free wavelength sensors

“…The proportion of industries using biosensor technology is increasing yearly. [1][2][3] Biosensing technology using optical metrology offers a more efficient and rapid testing method compared with conventional diagnostic methods. Consequently, developing related technologies for point-of-care testing (POCT) is actively underway.…”

Proposal of compact LSPR sensor system by filter-free wavelength sensor

“…Previously, we reported a filter-free wavelength sensor (FFS) capable of discriminating wavelength information in a single pixel without using optical components. 23,24) The basic principle is based on the wavelength dependence of the light absorption depth in silicon. 25,26) The potential depth W is formed by the photogate (PG) voltage located above the sensing region with the pn junction as shown in Figs.…”

“…Moreover, it identified a single wavelength with a high resolution above 0.1 nm. 23) This paper proposes a compact LSPR sensor system that integrates filter-free wavelength detection technology as a transducer. Figure 2 shows a proposed system concept in which an LSPR sensor and an FFS are integrated.…”