Realization of a filter-free wavelength image sensor and imaging system for visualization of wavelength information

In this study, we fabricated a filter-free wavelength image sensor for the two-dimensional visualization of wavelength information, in addition to light intensity, and realized an imaging system. In this sensor, the electrons generated in silicon in different distributions at each wavelength are divided into two parts by the potential peaks. The wavelength can be identified from the current ratio, and the light intensity can be determined from the total current. In the proposed structure, the pixel current is sequentially output by controlling the rows and columns. The layout was designed based on the proposed structure and was fabricated at the Toyohashi University of Technology LSI factory. An imaging system was constructed using operational amplifiers, A/D converters, and a microcontroller. The ratio and sum of the two signals obtained from the sensor responded linearly to the wavelength and light intensity. The wavelength response was independent of changes in the light intensity. Even when the spot was narrowed down, the response was obtained only at the corresponding pixel and succeeded in the simultaneous imaging of the intensity and wavelength. The above results can be applied to cell analysis, such as multiple fluorescence staining, where multiple fluorescence signals are detected simultaneously.