Multiplexing and encoding for reference switching

Patent metadata

Field	Value
Publication number	US-11740126-B2
Application number	US-202117351067-A
Country	US
Kind code	B2
Filing date	Jun 17, 2021
Priority date	Apr 21, 2016
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

Methods and systems for measuring one or more properties of a sample are disclosed. The methods and systems can include multiplexing measurements of signals associated with a plurality of wavelengths without adding any signal independent noise and without increasing the total measurement time. One or more levels of encoding, where, in some examples, a level of encoding can be nested within one or more other levels of encoding. Multiplexing can include wavelength, position, and detector state multiplexing. In some examples, SNR can be enhanced by grouping together one or more signals based on one or more properties including, but not limited to, signal intensity, drift properties, optical power detected, wavelength, location within one or more components, material properties of the light sources, and electrical power. In some examples, the system can be configured for optimizing the conditions of each group individually based on the properties of a given group.

First claim

What is claimed is:

1. A method for performing measurements of a sample at a set of positions using a measurement system, comprising:
retrieving, using a processor of the measurement system, a position encoding matrix associated with a set of positions;
selecting a first subset of positions of the set of positions from the position encoding matrix;
separating a set of wavelengths into groups of wavelengths;
retrieving a first wavelength encoding matrix associated with a first group of wavelengths of the groups of wavelengths;
emitting, using the measurement system, the first group of wavelengths into the sample; and
measuring, using the measurement system, an intensity for the first group of wavelengths returned from the sample at each position of the first subset of positions.

2. The method of claim 1 , further comprising:
retrieving a wavelength decoding matrix associated with the first group of wavelengths;
producing an associated first group of wavelength dependent signals at each position of the subset of positions by using the wavelength decoding matrix and the intensity measurements of the first group of wavelengths;
retrieving a second wavelength encoding matrix associated with a second group of wavelengths of the groups of wavelengths; and
measuring the intensity for each wavelength of the second group of wavelengths at each position of the first subset of positions.

3. The method of claim 1 , further comprising:
producing an associated first group of wavelength dependent signals at each position of the first subset of positions by using a wavelength decoding matrix associated with the first group of wavelengths and the intensity measurements of the first group of wavelengths; and
combining all wavelength dependent signals of the measured groups of wavelengths after all the groups of wavelengths are measured at each position of the first subset of positions.

4. The method of claim 1 , further comprising:
retrieving a wavelength decoding matrix associated with the first group of wavelengths;
producing an associated first group of wavelength dependent signals at each position of the subset of positions by using the wavelength decoding matrix and the intensity measurements of the first group of wavelengths;
after producing an associated first group of wavelength dependent signals, determining whether all groups of wavelengths have been measured.

5. The method of claim 4 , further comprising:
after determining that all groups of wavelengths have not been measured, retrieving a second wavelength encoding matrix associated with a second group of wavelengths of the groups of wavelengths;
measuring the intensity for each wavelength of the second group of wavelengths at each position of the second subset of positions.

6. The method of claim 5 , further comprising:
selecting a second subset of positions of the set of positions from the position encoding matrix;
separating the set of wavelengths into groups of wavelengths;
retrieving a third wavelength encoding matrix associated with a third group of wavelengths of the groups of wavelengths; and
measuring an intensity for each group of wavelength at each position of the subset of positions.

7. The method of claim 6 , wherein the first group of wavelengths and the third group of wavelengths are the same group of wavelengths.

8. The method of claim 4 , further comprising:
after determining that all groups of wavelengths have been measured producing an associated first group of wavelength dependent signals at each position of the first subset of positions by using a wavelength decoding matrix associated with the first group of wavelengths and the intensity measurements of the first group of wavelengths; and
combining all wavelength dependent signals of the measured groups of wavelengths after all the groups of wavelengths are measured at each position of the first subset of positions.

9. The method of claim 1 , wherein measuring the intensity for the first group of wavelengths at each position of the first subset of positions further comprises determining a set of signal values included in a signal intensity matrix.

10. The method of claim 1 , wherein measuring the intensity for the first group of wavelengths at each position of the first subset of positions further comprises measuring a reference intensity.

11. The method of claim 10 , wherein measuring intensity for the first group of wavelengths at each position of the first subset of positions and measuring the reference intensity occur simultaneously.

12. The method of claim 1 , further comprising:
determining that all groups of wavelengths have been measured producing an associated first group of wavelength dependent signals at each position of the first subset of positions by using a wavelength decoding matrix associated with the first group of wavelengths and the intensity measurements of the first group of wavelengths;
combining all wavelength dependent signals of the measured groups of wavelengths after all the groups of wavelengths are measured at each position of the first subset of positions; and
determining whether all the positions in the position encoding matrix have been measured.

13. The method of claim 12 , further comprising:
determining that all the positions in the position encoding matrix have been measured;
retrieving a decoding matrix associated with position; and
determining a set of wavelength and position dependent signals.

14. The method of claim 12 , further comprising:
determining that all the positions in the position encoding matrix have not been measured;
selecting a third subset of positions of the set of positions from the position encoding matrix;
separating the set of wavelengths into groups of wavelengths;
retrieving a third wavelength encoding matrix associated with a third group of wavelengths of the groups of wavelengths; and
measuring an intensity for each wavelength of the third group of wavelengths at each position of the third subset of positions.

15. A method for taking a measurement of a sample at a set of positions using a measurement system, comprising:
selecting a plurality of position encoding states using a position encoding matrix, wherein each of the plurality of position encoding states is associated with a corresponding subset of a set of positions;
for each position encoding state, measuring the sample using the measurement system to obtain a set of wavelength-dependent signals; and
determining, using the sets of wavelength-dependent signals and an inverse of the position encoding matrix, a plurality of nested signals, each of which is associated with a corresponding wavelength and position.

16. The method of claim 15 , wherein:
the method further comprises determining a first group of wavelengths associated with a wavelength encoding matrix;
measuring the sample using the measurement system to obtain the sets of wavelength-dependent signals comprises:
measuring each wavelength of a first group of wavelengths at each position of a corresponding first set of the set of positions; and
after measuring each wavelength of the first group of wavelengths, retrieving an inverse of the wavelength encoding matrix to create wavelength-dependent signals associated with a first set of positions.

17. The method of claim 16 , further comprising:
determining a second group of wavelengths associated with the wavelength encoding matrix;
measuring each wavelength of the second group of wavelengths at each position of a corresponding first subset of the set of positions;
dete

Assignees

• Apple Inc

Inventors

• Ridder Trent D
• Arbore Mark Alan
• Shambat Gary
• Chen Robert
• Simon David I
• Kangas Miikka M

Classifications

• G01J3/427 Primary

  Dual wavelengths spectrometry · CPC title

• G01J3/06 Primary

  Scanning arrangements {arrangements for order-selection} · CPC title

• G01J3/10 Primary

  Arrangements of light sources specially adapted for spectrometry or colorimetry · CPC title

• G01J3/108

  for measurement in the infrared range · CPC title

• G01J3/2803

  using photoelectric array detector · CPC title