Confocal microscope with photon re-allocation

Patent metadata

Field	Value
Publication number	US-12546980-B2
Application number	US-202118265640-A
Country	US
Kind code	B2
Filing date	Dec 9, 2021
Priority date	Dec 10, 2020
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

A scanning confocal photon-reassignment microscope is configured to operate in a coherent (reflectance or transmission) imaging mode and having a confocal pinhole the diameter of which is between 2 and 4 Airy units. The microscope can be used to observe viral particles in suspension.

First claim

The invention claimed:

1 . A scanning confocal photon-reassignment microscope comprising: a light source configured to generate at least one spatially coherent illuminating light beam at an illumination wavelength; a first optical system configured to apply an angular scan to said illuminating light beam; at least one microscope objective configured to receive as input the illuminating light beam output from the first optical system and to focus it on a sample, and to collect and collimate a light beam elastically scattered by said sample, called a signal beam; a second optical system, which is able to coincide in whole or in part with the first optical system, and which is configured to receive as input the signal beam collimated by the microscope objective, to apply to it an angular scan opposite to that applied to the illuminating light beam and to focus it in a first focal plane; a pinhole arranged in said first focal plane; a third optical system configured to collect the signal beam having passed through the pinhole, to collimate it and to apply to it an angular scan synchronized with that applied to the illuminating light beam and such that the product of its amplitude and the cross-sectional area of the collimated light beam in the third optical system is greater than the product of the amplitude of the scan applied by the second optical system and the cross-sectional area of the collimated light beam in the second optical system, and to focus it in a second focal plane; and a matrix image sensor arranged in the second focal plane; characterized in that: an assembly consisting of the microscope objective, the second optical system and the third optical system is configured to focus on the matrix image sensor said signal beam at the illumination wavelength; and in that the pinhole has a diameter, or greatest lateral dimension, of between 2 and 4 Airy units.

2 . The scanning confocal microscope as claimed in claim 1 , wherein at least the second optical system comprises a beam splitter to split the signal beam from the illuminating light beam.

3 . The scanning confocal microscope as claimed in claim 1 , wherein the light source is configured to emit a blue, violet or near-ultraviolet illuminating light beam.

4 . The scanning confocal microscope as claimed in claim 1 , wherein the light source is a laser.

5 . The scanning confocal microscope as claimed in claim 1 , wherein the microscope objective is an immersion objective having a numerical aperture greater than or equal to 1.

6 . The scanning confocal microscope as claimed in claim 1 , wherein the third optical system is configured to apply to the signal beam an angular scan such that the amplitude of said scan multiplied by the cross-sectional area of the beam is between 1.8 and 2.2 times the product of the amplitude of the angular scan applied to the illuminating light beam by the first optical system and the cross-sectional area of said beam.

7 . The scanning confocal microscope as claimed in claim 1 , configured to operate in reflectance, wherein: the first optical system comprises a first lens to focus the illuminating light beam, a pinhole arranged in the focal plane of said first lens to perform spatial filtering of the illuminating light beam, a beam splitter to reflect a portion of said beam, a second lens to collimate said portion of the illuminating beam, a first oscillating mirror or system of oscillating mirrors to apply to it said angular scan and an afocal system comprising a third and a fourth lens; the second optical system comprises said afocal system, said first oscillating mirror or system of oscillating mirrors, said second lens and said beam splitter, the latter being configured to transmit a portion of the signal beam, backscattered by the sample; and the third optical system comprises a fifth lens to collimate the signal beam having passed through the pinhole, a second oscillating mirror or system of oscillating mirrors to apply to it said angular scan synchronized with that applied to the illuminating light beam and a sixth lens to focus it in the second focal plane.

8 . The scanning confocal microscope as claimed in claim 7 configured to operate in reflectance, wherein the light source (SL′) is configured to generate a plurality of said illuminating light beams in parallel, these propagating through the optical system, whereby the microscope objective collects a plurality of respective signal beams, which then propagate along said second optical system, and comprising a matrix array of pinholes arranged in said focal plane, one for each said backscattered light beam, and wherein: the light source comprises a first array of microlenses to generate and focus said plurality of illuminating light beams; the scanning confocal microscope comprises at least one oscillating mirror having a reflective front face and a reflective rear face, the front face forming part of the first and second optical system and the rear face forming part of the third optical system; and the third optical system comprises a second array of microlenses to increase the cross-sectional area of the backscattered light beams incident on the rear face of the oscillating mirror by a factor between 1.8 and 2.2.

9 . The scanning confocal microscope as claimed in claim 1 , wherein the light source is configured to generate a plurality of said illuminating light beams in parallel, these propagating through the first optical system, whereby the microscope objective collects a plurality of respective signal beams, which then propagate along said second optical system, and comprising a matrix array of pinholes (MP) arranged in said second focal plane, one for each backscattered light beam.

10 . The use of a scanning confocal microscope as claimed in claim 1 , to observe viral particles in suspension.

11 . A method for observing a sample, comprising the steps of: generating at least one spatially coherent and collimated illuminating light beam at an illumination wavelength; applying to it an angular scan; focusing it on the sample by means of a microscope objective; collecting, by means of said or of another microscope objective, a light beam elastically scattered by the sample at said illumination wavelength, called a signal beam; applying to the signal beam an angular scan opposite to that applied to the illuminating light beam and focusing it in a first focal plane; carrying out spatial filtering of the signal beam by means of a pinhole arranged in said first focal plane, the pinhole having a diameter, or a greatest lateral dimension, of between 2 and 4 Airy units; collecting the signal beam having passed through the pinhole, collimating it and applying to it an angular scan synchronized with that applied to the illuminating light beam and such that the product of its amplitude and the cross-sectional area of the signal beam is greater than the product of the amplitude of the angular scan applied to the illuminating light beam and its diameter and focusing it in a second focal plane; and detecting the signal beam by means of a matrix image sensor arranged in the second focal plane.

Assignees

• Centre Nat Rech Scient
• Inst Doptique Graduate School
• Univ Bordeaux
• Centre National De La Reserche Scient
• Inst D Optique Graduate School

Inventors

• Aguilar Alberto
• Bon Pierre

Classifications

• G02B21/33

  Immersion oils {, or microscope systems or objectives for use with immersion fluids} · CPC title

• G02B21/008

  Details of detection or image processing, including general computer control · CPC title

• G02B21/0072 Primary

  details concerning resolution or correction, including general design of CSOM objectives · CPC title

• G02B21/0048

  scanning mirrors, e.g. rotating or galvanomirrors, MEMS mirrors · CPC title

• G02B21/082

  for incident illumination only · CPC title