US 2006/0061766 A1Published application

Method and device for measuring a light flux backscattered by a dispersed medium, unperturbed by interface reflections

AssigneeFormulaction

InventorLaurent Brunel

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Abstract

A method for measuring a light flux backscattered by a dispersed medium located on one first side of a wall, by interaction with a plurality of light rays emitted from the second opposite side of the wall where the dispersed medium is located and towards the latter, the plurality of light rays being adapted to pass through the wall and being backscattered at least partly by the dispersed medium towards reception elements arranged on the second side of the wall. The method includes: emitting the plurality of light rays towards the dispersed medium and through the wall so as to form a backscattering spot having a central disc whose center corresponds to the luminous barycenter of the spot and whose radius is equal to four times the maximum free travel path (l*max) of the dispersed medium.

Claims30

Dependent claims

Method for measuring a light flux (11) backscattered by a dispersed medium (12) located on a first (13) side of a wall (14), by interaction with a plurality of light rays (15) emitted from the second (16) side of said wall which is opposite the first wall, where the dispersed medium is located and in the direction of the latter, said plurality of light rays being able to traverse said wall and being backscattered at least partially by said dispersed medium in the direction of receiving means (17) located on the second side of the wall, characterised in that said method comprises at least the following steps:

emitting said plurality of light rays (15) in the direction of said dispersed medium and through said wall (14) so that said dispersed medium is able to emit in turn, through said wall, a plurality of backscattered light rays (11) with the aim of forming a backscattering spot (19) in which at least one central zone (20) in the form of a disc is defined, the centre (21) of which corresponds to the luminous barycentre of the backscattering spot (19) and the radius (36) of which is equal to four times the maximum free travel path (l*max) of said dispersed medium, said backscattering spot (19) being able to be imaged at least in part on said receiving means (17),
forming said backscattering spot (19) from backscattered light rays which have traversed said wall and are free, at least according to a direction (22) extending from the luminous barycentre of said backscattering spot, of light rays which have emanated from said central zone and have undergone a total reflection on the surface (30) forming the interface of said wall (14) with said second (16) side,
measuring at least one spatial sample of a profile of the light flux in said thus obtained backscattering spot (19), extending in said at least one direction (22).

Device (10) for measuring a light flux (11) backscattered by a dispersed medium (12) located on a first (13) side of a wall (14), by interaction with a plurality of light rays (15) emitted from the second (16) side of said wall which is opposite the first side, where said dispersed medium is located and in the direction of the latter, said plurality of light rays being able to traverse said wall and being backscattered at least partially by said dispersed medium in the direction of receiving means (17) located on the second side of the wall, said wall being able to be traversed by said emitted and backscattered light rays, and to be in contact with said dispersed medium, said device being characterised in that it comprises:

means (18) for emitting, towards said wall, a light radiation (15) which is able to traverse the wall (14) and to reach said dispersed medium, so that the latter can emit in turn, through said wall, a plurality of backscattered light rays (11) with the aim of forming a backscattering spot (19) in which at least one central zone (20) in the form of a disc is defined, the centre (21) of which corresponds to the luminous barycentre of the backscattering spot and the radius (36) of which is equal to four times the maximum free travel path (l*max) of said dispersed medium, said backscattering spot (19) being able to be imaged at least in part on said receiving means (17),
means (17) for receiving light radiation backscattered by said dispersed medium through said wall and intended to form said backscattering spot, said receiving means covering at least one direction (22) extending from the luminous barycentre of said spot,
means (23) for suppressing, from light rays backscattered by said dispersed medium, light rays (33) which have emanated from said central zone (20) and have undergone a total reflection on the surface (30) forming the interface of said wall (14) with said second side (16),
means (24) for measuring a spatial sample of the profile of the light flux received by one part at least of said receiving means.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 10/519,460Filed 25 Jun 2003
Priority: FR 02/082352 Jul 2002
Published: 23 Mar 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G01N 21/0303
Cuvette constructions: optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment
G01N 15/0227
By optical means: using imaging; using holography
G01N 21/51
Within a body or fluid: inside a container, e.g. in an ampoule
G01N
Investigating or analysing materials by determining their chemical or physical properties