Visualizing early frog development with motion-sensitive 3-D optical coherence microscopy.

A motion-sensitive en-face-scanning 3-D optical coherence microscope (OCM) has been designed and constructed to study critical events in the early development of plants and animals. We describe the OCM instrument and present time-lapse movies of frog gastrulation, an early developmental event in which three distinct tissue layers are established that later give rise to all major organ systems. OCM images constructed with fringe-amplitude data show the mesendoderm migrating up along the blastocoel roof, thus forming the inner two tissue layers.

Role of beat noise in limiting the sensitivity of optical coherence tomography.

The sensitivity and dynamic range of optical coherence tomography (OCT) are calculated for instruments utilizing two common interferometer configurations and detection schemes. Previous researchers recognized that the performance of dual-balanced OCT instruments is severely limited by beat noise, which is generated by incoherent light backscattered from the sample. However, beat noise has been ignored in previous calculations of Michelson OCT performance.

An optical coherence microscope for 3-dimensional imaging in developmental biology.

An optical coherence microscope (OCM) has been designed and constructed to acquire 3-dimensional images of highly scattering biological tissue. Volume-rendering software is used to enhance 3-D visualization of the data sets. Lateral resolution of the OCM is 5 mm (FWHM), and the depth resolution is 10 mm (FWHM) in tissue.

Measurement of the lifetime of the atomic cesium 5(2)D(5/2) state with diode-laser excitation.

The lifetime of the atomic cesium 5(2)D(5/2) state was measured with time-correlated single-photon counting spectroscopy. Ground-state cesium atoms were excited with a diode laser by use of an electric quadrupole transition. Analysis of the exponential decay of the cascade photons from the 6(2)P(3/2) state yields a 5(2)D(5/2) lifetime of 1225(12) ns.