Full-field interferential imaging systems and methods

A full-field optical-coherence-tomography system for imaging a sample, comprising:

• an illumination channel comprising a light source for emitting incident light waves;
• an interferometer comprising:
• at least one first objective, the light source being arranged in an image focal plane of the first objective or in a plane conjugate with an image focal plane of the first objective;
• and
• a splitting element suitable for receiving, via an entrance face, the incident light waves and suitable for forming an object arm intended to receive the sample and a reference arm in which is arranged a reflecting device;
• and wherein the splitting element has a reflection coefficient and a transmission coefficient that are not equal, such that the proportion of the optical power of the incident light waves sent to the object arm is strictly higher than the proportion of the optical power of the light waves sent to the reference arm;
• the reflecting device is suitable for directing the reflected incident light waves in a direction that is different from the direction of incidence, that is to say along an optical path making an angle α with an incident optical path, and
• the interferometer is suitable for producing, when the sample is placed in the object arm of the interferometer, at each point of an imaging field, interference between a reference wave obtained by reflection of incident light waves from an elementary surface of the reflecting device corresponding to said point of the imaging field and an object wave obtained by backscatter of incident light waves by a voxel of a slice of the sample at a given depth, said voxel corresponding to said point of the imaging field, angle α allowing angular spatial separation between the incident light wave and the reference wave;
• a detection channel comprising a device for acquiring two-dimensional images, and wherein the device for acquiring two-dimensional images is positioned in a conjugate plane of the reflecting device and suitable for acquiring two-dimensional interferometric signals resulting from the interference produced at each point of the imaging field;
• the illumination channel and the detection channel comprise a common channel at least between said entrance face of the splitting element and a reflecting element, said reflecting element separating the illumination channel and the detection channel and being positioned in an image focal plane of said first objective, or in a conjugate plane of said image focal plane of the first objective, said reflecting element comprising a mirror that is inclined with respect to an optical axis of the first objective, and whose shape and dimensions are suitable, in combination with said angular spatial separation, for letting pass, in the detection channel, at least one portion of the light waves directed by the reflecting device of the reference arm and for letting pass, in the illumination channel, at least one portion of the incident light waves;
• a processing unit configured to calculate an image of the sample from said two-dimensional interferometric signals.