Ultra-low-cost and high-fidelity NIR-II confocal laser scanning microscope with Bessel beam excitation and SiPM detection

The NIR-II based CLSM has problems such as expensive detector and reduced image resolution. Here, by simultaneously using a low-cost silicon photomultiplier (SiPM) as a detector and a Bessel beam as an excitation, we developed an ultra-low-cost and high-fidelity NIR-II confocal laser scanning microscope. The introduction of Bessel beam compensates to some extent for the weakening of spatial resolution caused by the increase in the wavelength of light in the NIR region. The use of SiPM reduces the cost of NIR-II fluorescence detection module in CLSM, while enabling the detection of ultra-broadband fluorescence signals spanning visible to NIR-II regions.