Confocal Microscopy


Focusing into a turbid light-scattering medium

A Gaussian beam is delivered to the medium by a lens (horizontal black line) via an index-matching medium. The lens is moved vertically to scan the focus down through the medium. The fluence rate transport, T [W/cm2 per W delivered] = [1/cm2], is shown versus radial position r and depth z using a logarithmically scaled colorbar (101 to 105 [1/cm2]). Lower curves show the transport along the central z axis, illustrating how the focus moves down into the medium. Lower left shows T at the focus versus optical depth. Lower right shows T(z). (The medium has a reduced scattering coefficeint of 400 cm-1 and an anistropy of scattering of g = 0.90.)