ANALYTICAL METHOD AND APPARATUS

• US 20080030738A1
• Filed: 08/15/2007
• Published: 02/07/2008
• Est. Priority Date: 02/04/1997
• Status: Active Grant

• Current Assignee: GE Healthcare Bio-Sciences AB (General Electric Company)
• Original Assignee: Biacore AB
• Inventors: IVARSSON, BENGT
• Granted Patent: US 7,460,236 B2
• Time in Patent Office: Days
• US Class Current: 356/445
• CPC Class Codes: G01B 11/0625 with measurement of absorption or reflection
• CPC Class Codes: G01N 2021/212 Arrangement with total internal reflection
• CPC Class Codes: G01N 2021/215 Brewster incidence arrangement
• CPC Class Codes: G01N 21/552 Attenuated total reflection
• CPC Class Codes: G01N 21/553 and using surface plasmons fluorescence excitation G01N21/648; enhanced Raman G01N21/658

Abstract

A method of examining thin layer structures on a surface for differences in respect of optical thickness, which method comprises the steps of: irradiating the surface with light so that the light is internally or externally reflected at the surface; imaging the reflected light on a first two-dimensional detector; sequentially or continuously scanning the incident angle and/or wavelength of the light over an angular and/or wavelength range; measuring the intensities of light reflected from different parts of the surface and impinging on different parts of the detector, at least a number of incident angles and/or wavelengths, the intensity of light reflected from each part of the surface for each angle and/or wavelength depending on the optical thickness of the thin layer structure thereon; and determining from the detected light intensities at the different light incident angles and/or wavelengths an optical thickness image of the thin layer structures on the surface. According to the invention, part of the light reflected at said surface is detected on a second detector to determine the incident angle or wavelength of the polarized light irradiating the surface. An apparatus for carrying out the method is also disclosed.

Claims

1. :

A method for analysis of a sensor surface comprising a plurality of individual subzones, the method comprising;

irradiating the sensor surface with a collimated beam of light so that the light is reflected at the surface,

imaging reflected light on a detector such that each subzone of the sensor surface corresponds to a respective area of the detector,

scanning the incident angle of the beam of light at the sensor surface over an angular range,

measuring the intensities of light imaged on the different areas of the detector at different incident angles to create a series of images,

correlating each image to a specific incident angle, and determining for each subzone of the sensor surface the variation of the intensity of imaged light on the different detector areas with the incident angle.

2. :

The method according to claim 1, wherein the light is totally internally reflected at the sensor surface.

3. :

The method according to claim 1, wherein the light is coupled to the sensor surface via a prism.

4. :

The method according to claim 1, wherein the light is coupled to the sensor surface via a grating.

5. :

The method according to claim 1, wherein the image forming is based on surface plasmon resonance at the sensor surface.