Label free deep penetration single photon microscopic imaging with ultralong anti-diffracting beam.

Label free single photon microscopic imaging has natural advantages in noninvasive in vivo tissue imaging such as high resolution and rapid imaging speed. Although label free multi-photon microscopy can be used for imaging thick tissue samples, it requires high excitation light power and is phototoxic to the samples. Conventional label free single photon microscopy requires lower excitation light power, but it has limited imaging depth. Observing some highly scattering thick tissue samples with single photon microscopy is a great challenge. To solve the problem, we developed a label free deep penetration single photon microscopic imaging technique with an ultralong anti-diffracting (UAD) beam. The penetrating ability of the UAD beam was verified by passing through turbid media and performed with autofluorescence of chloroplasts in fresh Epipremnum aureum leaves. Benefiting from the anti-diffracting properties and the elongated focal depth of the UAD beam, single photon UAD microscopy has deeper penetration depth and better anti-scattering ability and is one of the ideal methods to observe the deep structure of biological samples. [ABSTRACT FROM AUTHOR]