High-resolution three-dimensional imaging inside biological media using white-light interference microscopy

We present a white-light interference microscope designed to produce high-resolution three-dimensional images of biological media. This technique is an alternative to conventional optical coherence tomography (OCT). The experimental setup is based on a Linnik interferometer illuminated with a tungsten halogen lamp. En face tomographic images are obtained in real-time without scanning by computing the difference of two phase-opposed interferometric images recorded by a high-resolution CCD camera. The short coherence length of the source and the compensation of dispersion mismatch in the interferometer arms yield an optical sectioning ability with 0.8 mum resolution in water. Transverse resolution of 1.0 mum is achieved by using high numerical aperture microscope objectives. A shot-noise limited detection sensitivity of 86 dB can be reached with 2 s acquisition time. High-resolution images of the Xenopus Laevis tadpole are shown.