Full-field optical coherence tomography imaging method

Patent metadata

Field	Value
Publication number	US-12329455-B2
Application number	US-202017786714-A
Country	US
Kind code	B2
Filing date	Dec 18, 2020
Priority date	Dec 18, 2019
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

A full-field optical coherence tomography imaging method, FFOCT, using a system comprising an FFOCT device and a sample, the sample comprising a layer of interest to be imaged, the FFOCT device comprising an incoherent light source, an imager, a beam splitter defining a sample arm and a reference arm, the method comprising—generating sample light containing interest light originating from the layer of interest and reference light traveling from the reference arm, —acquiring an image from reference light and sample light combined in the beam splitter; wherein at least one of the sample arm and the reference arm comprises an optical curvature compensator that modifies a transverse variation distribution of an optical path length to match the transverse variation distributions of the optical path lengths travelled by the reference light and the interest light incident on the imager.

First claim

The invention claimed is:

1. An imaging method,
the method performing a full-field optical coherence tomography imaging, FFOCT,
the method comprising acquiring a bidimensional en face FFOCT image of a layer of interest at a depth within a sample,
the method using a system comprising a FFOCT device,
the sample comprising the layer of interest that is to be imaged,
the FFOCT device comprising:
a spatially incoherent light source,
an imager,
a beam splitter defining a sample arm and a reference arm, the sample being arranged at an extremity of the sample arm,

wherein the method comprises:
simultaneously illuminating the sample arm and the reference arm at an illumination instant with an illuminating light emitted by the incoherent light source to generate sample light travelling from the sample into the extremity of the sample arm along a sample optical path and reference light traveling in the reference arm to the beam splitter along a reference optical path,
acquiring a bidimensional en face FFOCT image of the layer of interest with the imager from reference light and sample light combined in the beam splitter;

wherein the sample light contains interest light derived from the illuminating light emitted at the illumination instant and originating from the layer of interest of the sample, the interest light having travelled a first optical path length when entering the sample arm, the first optical path length having a curved profile of transverse variation distribution,
wherein reference light incident on the imager has travelled a reference optical path length along the reference optical path, and interest light incident on the imager has travelled a second optical path length,
wherein the reference arm comprises an optical curvature compensator that modifies a transverse variation distribution of the reference optical path length travelled by the reference light incident on the imager to compensate the curved profile of transverse variation distribution of the first optical path length, so that the transverse variation distribution of the reference optical path length travelled by the reference light incident on the imager and the transverse variation distribution of the first optical path length travelled by the interest light incident on the imager coincide, resulting in the interest light originating from the layer of interest interfering with the reference light and the imager imaging the layer of interest over a field of view of the imager to form the bidimensional en face FFOCT image acquired by the imager,
wherein the optical curvature compensator is a curved reflector having a curved reflecting surface, the curved reflector arranged at an end of the reference arm opposed to the beam splitter.

2. The method of claim 1 , wherein a curved profile of the transverse variation distribution of the first optical path length has an absolute radius of curvature comprised between 4 and 50 millimetres.

3. The method of claim 1 , wherein the transverse variation distribution of the reference optical path length travelled by the reference light incident on the imager and the transverse variation distribution of the second optical path length travelled by the interest light incident on the imager have a difference of absolute radius of curvature below 2 millimetres.

4. The method of claim 1 , wherein the reflector has a reflectance below 25%.

5. The method of claim 1 , wherein the curved reflecting surface of reflector is an optical lens.

6. The method of claim 1 , wherein the curved reflecting surface of reflector is a deformable mirror.

7. The method of claim 1 , wherein the optical curvature compensator is a plate of material having a refractive index and a thickness in the direction of the reference optical path or the sample optical path.

8. The method of claim 1 , wherein the optical curvature compensator is a configurable optical curvature compensator, and the FFOCT device comprises a control loop configured to analyse an acquired image and derive a command to change a configuration of an optical curvature compensator, each configuration defining a different modification of the transverse variation distribution of an optical path length.

9. The method of claim 1 , comprising:
acquiring a first bidimensional en face FFOCT image of the layer of interest with the imager from reference light and sample light combined in the beam splitter;
determining whether the curved profile of transverse variation distribution of the first optical path length has been compensated by the optical compensator;
if the curved profile of the transverse variation distribution of the first optical path length is determined as not compensated by the optical compensator, modifying the optical compensator to compensate the curved profile of transverse variation distribution of the first optical path length so that; and
acquiring a second bidimensional en face FFOCT image of the layer of interest with the imager from reference light and sample light combined in the beam splitter.

10. A full-field optical coherence tomography, FFOCT, device comprising:
a spatially incoherent light source configured to emit an illuminating light at an illumination instant,
an imager configured to acquire a bidimensional en face FFOCT image of a layer of interest,

a beam splitter defining a sample arm and a reference arm, the sample containing the layer of interest at a depth within the sample and being arranged at an extremity of the sample arm,
wherein at least one of the sample arm and the reference arm comprises an optical curvature compensator configured to modify a transverse variation distribution of an optical path length to compensate a curved profile of transverse variation distribution of the first optical path length travelled by an interest light derived from the illuminating light emitted at the illumination instant and originating from the layer of interest of the sample when the interest light enters the sample arm, and
wherein the FFOCT device is configured to perform the method of claim 1 to acquire a bidimensional en face FFOCT image of the layer of interest at a depth within the sample.

11. An imaging method,
the method performing a full-field optical coherence tomography imaging, FFOCT,
the method comprising acquiring a bidimensional en face FFOCT image of a layer of interest at a depth within a sample,
the method using a system comprising a FFOCT device,
the sample comprising the layer of interest that is to be imaged,
the FFOCT device comprising:
a spatially incoherent light source,
an imager,
a beam splitter defining a sample arm and a reference arm, the sample being arranged at an extremity of the sample arm,

wherein the method comprises:
simultaneously illuminating the sample arm and the reference arm at an illumination instant with an illuminating light emitted by the incoherent light source to generate sample light travelling from the sample into the extremity of the sample arm along a sample optical path and reference light traveling in the reference arm to the beam splitter along a reference optical path,
acquiring a bidimensional en face FFOCT image of the layer of interest with the imager from reference light and sample light combined in the beam splitter;

wherein the sample light contains interest light derived from the illuminating light emitted at the illumination instant and originating from the layer of interest of the sample, the interest light having travelled a first optical path length when entering the sample arm, the first optical path length having a curved profile of transverse variation distribution,
wherein reference light incident on the imager has tr

Assignees

• Paris Sciences Et Lettres
• Centre Nat Rech Scient
• Ecole Superieure Physique & Chimie Ind Ville De Paris

Inventors

• Mazlin Viacheslav
• Baracal De Mece Pedro Francisco
• Boccara Albert Claude

Classifications

• A61B5/0066

  Optical coherence imaging · CPC title

• A61B3/102 Primary

  for optical coherence tomography [OCT] · CPC title

• G01B9/02091

  Tomographic interferometers, e.g. based on optical coherence · CPC title

• G01B9/02039 Primary

  by matching the wavefront with a particular object surface shape · CPC title