Near-infrared-II confocal microscope and methods of use

A near-infrared (NIR) confocal imaging device, comprising:

• (a) a light source constructed to illuminate a sample using an excitation light and to produce an emission light, from the sample, in a NIR range;
• (b) an optical path from the light source to and through an objective lens directed to the sample;
• (c) a detector constructed to detect NIR light at a wavelength between about 800 nm to 1700 nm;
• (d) a fixed beam splitter separating excitation light and emission light, wherein the emission light is directed to the detector;
• (e) a translational stage configured to support the sample and operative to cause a raster scanning movement relative to the objective lens during imaging and further comprising one or more actuators to move the translational stage in three dimensions during scanning;
• and
• (f) a computer comprising instructions which cause the confocal imaging device to:
• synchronize the scanning of the translational stage with the detector,
• detect emitted NIR light from the sample at a wavelength between about 800 nm to 1700 nm,
• move the translational stage in an x-y direction under control of the computer to obtain a raster scan of the sample,
• acquire data of individual pixels received by the detector at specified locations during scanning of the translational stage, and
• produce an image of the sample.