Sum Frequency Generation Confocal Microscopy Observation of a Fish Scale

Abstract

An optical sum frequency generation (SFG) microscopy image of a fish scale of Pagrus major was observed. Its SFG spectra were also measured and were compared with that of collagen of Achilles tendon of a cow (Bos taurus). From this comparison, the peak near 2950 cm^-1 in the fish scale spectrum was assigned to the fish collagen. The two collagen spectra showed different line shapes and widths owing to a difference in the background nonlinearity. In the SFG image of the fish scale cross section, stronger signal was observed from the sea side than from the body side. [DOI: 10.1380/ejssnt.2014.259]