We propose a 3D imaging technique based on the combination of full-field swept-source optical coherence microscopy (FF-SSOCM) with low spatial coherence illumination and a special numerical processing that allows for numerically focused coherent-noise-free imaging without mechanical scanning in longitudinal or transversal directions. We show, both theoretically and experimentally, that the blurring effects arising in FF-SSOCM due to defocus can be corrected by appropriate numerical processing even when low spatial coherence illumination is used. A FF-SSOCM system was built for testing the performance of this technique. Coherent-noise-free imaging of a sample with longitudinal extent exceeding the optical depth of field is demonstrated without displacement of the sample or any optical element.

Full-field optical coherence microscopy (FF-OCM) with isotropic spatial resolution of 0.5 μm (in water), at 700 nm center wavelength, is reported. A theoretical study of the FF-OCM axial response is carried out for maximizing the axial resolution of the system, considering the effect of optical dispersion. The lateral resolution is optimized by using water-immersion microscope objectives with a numerical aperture of 1.2. This ultrahigh-resolution FF-OCM system is applied to animal and human skin tissue imaging, revealing ultra-fine in-depth structures at the sub-cellular level.

An original single-objective, full-field optical coherence microscopy system is reported that is capable of imaging both the phase and the amplitude of semi-transparent samples over a field of view of 17.5  mm×17.5  mm with an axial sectioning resolution of 1.5 μm. A special stack acquisition arrangement ensures optimal reachable imaging depth. Several phase-shifting interferometry algorithms for phase measurement with broadband light are compared theoretically and experimentally. Using the phase information, noninvasive depth-resolved topographic images of multilayer samples are produced to characterize each layer by measuring their defects and curvature with a nanometric scale precision. Using the amplitude information, tomographic images with a constant detection sensitivity of ∼80  dB through the entire field of view are obtained and applied to biological specimens.

To cite this version:Antoine Federici, Arnaud Dubois. Three-band, 1.9-µm axial resolution full-field optical coherence microscopy over a 530-1700 nm wavelength range using a single camera.

Full-field optical coherence microscopy (FF-OCM) is an established optical technology based on low-coherence interference microscopy for high-resolution non-invasive three-dimensional imaging of semi-transparent samples. We present an extension of the technique setting up an achromatic imaging system over a spectral range extending from 530 nm to 1700 nm, to provide tomographic images in three distinct bands centered at 635 nm, 870 nm and 1170 nm. Image contrast enhancement as well as sample characterization is performed using the conventional RGB color channel representation. Light is emitted by a halogen lamp and then separates into two arms of a Linnik-type interferometer with microscope objectives placed in each arm. The images are projected onto a visible to short-wavelength infrared detector based on an InGaAs photodiode array. Enface oriented tomographic images are obtained by arithmetic combination of four phase-shifted interferometric images. Great care was taken to reach similar performances in the three bands. An axial resolution of ~1.9µm and a transverse resolution of ~2.4µm are achieved in the three bands. A dynamic dispersion compensation system is set up to preserve axial resolution and signal intensity level when the imaging depth is varied. Images of biological samples revealing their spectral properties are shown as illustration of improved detection capability with enhanced contrast.

No abstract

No abstract

No abstract