Refractive-index mismatch in conventional confocal microscopy produces severe degradation on axial resolution of
sectioning image because the spherical aberration is generated in specimen. In this study, we propose a polarized
photon-pairs confocal laser scanning microscope (PCLSM) in which a two-frequency linear polarized photon-pairs
(LPPPs) laser beam is produced. The common-path propagation of LPPPs integrated with optical heterodyne technique
not only can reduce the spherical aberration but also decreases scattering effect in specimen at same time. Therefore, the
better axial and lateral resolutions of the sectioning image are produced simultaneously. In the experiment, a verification
and comparison between PCLSM and conventional confocal laser scanning microscope (CLSM) on the ability of
cancellation of spherical aberration induced by cover glass are demonstrated experimentally. Finally, the ability of
PCLSM which can decrease the spherical aberration based on the common-path propagation of LPPPs associated with
polarization gating, spatial coherence gating and spatial filtering gating is discussed.
A photon pair density wave (PPDW) is initiated and compared with the conventional defused photon density wave (DPDW) to verify its optical properties generated by correlated parallel polarized pair photons propagating in a scattering medium. An optical heterodyne signal is generated by the scattered correlated pair photons in the scattering
medium. However, the phase delay of the signal depends upon the beat frequency and the distance between source and detector. This is similar to DPDW at the lower modulated frequency of laser source in frequency domain. Spherical wave fronts of constant attenuated intensity and the phase delay of PPDW are observed in a homogenous
scattering medium by using a lock-in amplifier. The assumption that polarized photon pairs propagating as photon density wave in a multiple scattering medium is verified experimentally. Optical properties of PPDW in the scattering medium are demonstrated successfully.
The angular distribution of the photon pairs of a Zeeman laser scanning confocal microscope (ZLSCM) is measured in turbid media. By scanning the pinhole at different locations on a focal plane, the angular distribution of the snake photon pairs that is contributed by the object plane in the scattering medium is measured. The narrower width of the angular distribution of the snake photon pairs implies the better performance of the depth resolution of ZLSCM in turbid media. In this study, the dependence between depth resolutions of ZLSCM with respect to different vol. % concentrations of the scattering medium is observed. In addition, the correlation between angular distribution and depth resolution in different concentrations is also demonstrated and discussed.