We present a novel detection scheme for Fourier domain optical coherence microscopy (FDOCM). A Bessel-like
interference pattern with a strong central lobe was created with an axicon lens. This pattern was then imaged by a
telescopic system into the sample space to obtain a laterally highly confined illumination needle, extending over a long
axial range. For increased efficiency, the detection occurs decoupled from the illumination, avoiding a double pass
through the axicon. Nearly constant transverse resolution of ~1.5&mgr;m along a focal range of 200&mgr;m with a maximum
sensitivity of 105dB was obtained. A broad bandwidth Ti:Sapphire laser allowed for an axial resolution of 3&mgr;m in air,
providing the nearly isotropic resolution necessary to access the microstructure of biological tissues. Together with the
speed- and sensitivity-advantage of FDOCT, this system can perform in vivo measurements in a minimally invasive way.
Tomograms of the mouse mammary gland and the mouse follicle, recorded in vitro, revealed biologically relevant
structural details. Images acquired with classical microscopy techniques, involving stained and fluorescent samples,
validate these structures and emphasize the high contrast of the tomograms. It is comparable to the contrast achieved
with classical techniques, but employing neither staining, labeling nor slicing of the samples, stressing the high potential
of FDOCM for minimally invasive in vivo small animal imaging.