Advanced systems and methods for interferometric particle detection and detection of particles having small size dimensions

Patent metadata

Field	Value
Publication number	US-11988593-B2
Application number	US-202016953987-A
Country	US
Kind code	B2
Filing date	Nov 20, 2020
Priority date	Nov 22, 2019
Publication date	May 21, 2024
Grant date	May 21, 2024

Abstract

The present invention relates to interferometric detection of particles and optical detection of particles having size dimensions less than or equal to 100 nm. Systems and methods are provided exhibiting enhanced alignment and stability for interferometric detection of particles and/or optical detection of particles having size dimensions less than or equal to 100 nm. Systems and methods are provided that include compensation means for mitigating the impact of internal and external stimuli and changes in operating conditions that can degrade the sensitivity and reliability of particle detection via optical methods, including interferometric-based techniques and/or systems for optical detection of particles having size dimensions less than or equal to 100 nm.

First claim

We claim:

1. A particle detection system comprising:
optical components, the optical components including:
a flow cell for flowing a fluid containing particles;
an optical source for generating one or more beams of electromagnetic radiation;
a beam shaping optical system for passing said one or more beams of electromagnetic radiation through said flow cell, thereby generating electromagnetic radiation scattered by said particles; and
at least one optical detector array for receiving the scattered electromagnetic radiation from said flow cell, wherein said optical source, beam shaping optical system and optical detector array are configured to allow for detection of particles having size dimensions less than or equal to 100 nm;

an optical bench, wherein the flow cell, the optical source, the beam shaping optical system, and the at least one optical detector array are supported by the optical bench
a particle detector housing enclosing the optical bench and the optical components thereon such that the optical bench and the optical components thereon are thermally isolated from an external environment;
an active temperature control system comprising:
a first closed loop temperature control system configured to control the temperature of the optical source, the first closed loop temperature control system comprising:
a first thermoelectric cooler and a first temperature sensor, the first thermoelectric cooler and the first temperature sensor being thermally coupled to an inner space of the optical source;
a first temperature controller in electrical communication with the first thermoelectric cooler and the first temperature sensor, wherein the first temperature controller is configured to control the temperature of the inner space of the optical source; and

a second closed loop temperature control system configured to control the temperature of an interior volume of the particle detector housing, the interior volume being defined by one or more interior surfaces of the housing, wherein the optical bench and the optical components thereon, including the optical source, are disposed in the interior volume of the housing, the second closed loop temperature control system comprising:
a second thermoelectric cooler configured to cool a heat transfer medium circulating within the housing and a second temperature sensor being thermally coupled to the interior volume of the housing;
a fluid circulation device disposed within the housing and configured to circulate the heat transfer medium throughout; and
a vibration isolation device configured to reduce vibrations transmitted from the fluid circulation device to the optical bench;

wherein the active temperature control system is configured to control a temperature of the interior volume of the enclosure including the optical bench and the components thereon; and
wherein the system is further configured to control at least one of: pressure, extent of vibrations, and extent of acoustic waves, or any combination of these to be within a selected tolerance, so as to maintain a high signal-to-noise ratio during said detection of said particles.

2. The system of claim 1 , wherein said optical source, beam shaping optical system and optical detector array are configured to provide at least one of structured beam interferometric detection of said particles by passing a structured probe beam of coherent electromagnetic radiation through said flow cell, or heterodyne interferometric detection of said particles by collecting off-axis scattered light and combining the off-axis scattered light scattered light with a reference beam to create the interferometric signal.

3. The system of claim 1 , wherein said optical source and optical detector array are configured to provide structured dark beam interferometric detection of said particles.

4. The system of claim 1 , wherein said optical detector array is positioned in optical communication with said flow cell for receiving incident electromagnetic radiation transmitted through said flow cell and electromagnetic radiation scattered by said particle, and wherein said electromagnetic radiation scattered by said particle comprises forward scattered electromagnetic radiation.

5. The system of claim 1 , wherein said optical detector array is positioned in optical communication with said flow cell for receiving incident electromagnetic radiation transmitted through said flow cell and electromagnetic radiation scattered by said particle, and wherein said incident electromagnetic radiation transmitted through said flow cell and said electromagnetic radiation scattered by said particle undergo constructive and/or destructive optical interference.

6. The system of claim 1 , wherein said optical detector array is provided at a scattering angle that is within 5 degrees of zero degrees relative to the optical axis of the incident beam.

7. The system of claim 1 , wherein said system provides interferometric detection of said particles and/or optical detection of particles having size dimensions less than or equal to 100 nm without significant performance degradation of the internal particle counting process when subjected to one or more of the following conditions:
i. a change in T up to 5° C. at a rate of less than 1° C./hr;
ii. a change in P up to 300 mbar;
iii. a change in beam path length up to 10 mm;
iv. a change in beam focus position up to 2 mm;
v. a change in beam power of up to 20%;
vi. vibration level I up to 200 microns/sec;
vii. a change in beam angle up to +/−5 degrees;
viii. a condition of laser noise up to <2% (RMS);
ix. a change in M 2 of laser up to <1.3;
x. a change in linewidth of laser up to <100 MHz;
xi. a change in RH up to <50%;
xii. controlling electric (line power) stability and noise; and
xiii. any combinations of these.

8. The system of claim 1 , wherein said active temperature controller is provided for compensating for changes in said system parameters in response to ambient conditions, internal stimuli, external stimuli or any combination of these so as to prevent performance degradation due to optical alignment shifts to maintain a high signal-to-noise ratio during said detection of said particles.

9. The system of claim 8 , wherein the flow cell, optical source, beam shaping optical system, optical detector array or any combination of these are configured to provide passive isolation for compensating for changes in said system parameters in response to ambient conditions, internal stimuli or external stimuli, wherein said passive isolation is provided by one or more of the following features:
xiv. incorporation of one or more vibration isolators;
xv. incorporation of one or more adhesive layers in lenses;
xvi. incorporation of one or more thermoset or thermoplastic mechanical restraints;
xvii. reduced size and/or mass of optical source and components;
xviii. incorporation of lens mounts having natural frequency greater than or equal to 150 Hz
xix. incorporation of flow cell mechanically isolated from optical source and components;
xx. coefficient of thermal expansion matched materials; and
xxi. low coefficient of thermal expansion optical components.

10. The system of claim 8 , wherein said optical source provides a coherent incident beam or a Gaussian incident beam.

11. The system of claim 8 , wherein said optical source comprises one or more shaping and/or combining optical elements for generating said one or more beams of electromagnetic radiation, wherein said one or more shaping and/or combining optical elements are diffractive elements, polarizing elements, intensity modulating elements, phase modulating elements or any combination of these.

Assignees

• Particle Measuring Syst

Inventors

• Ellis Timothy A
• Bonino Chris
• Knollenberg Brian A
• Lumpkin James
• Rodier Daniel
• Sehler Dwight
• Moghaddam Mehran Vahdani
• Ramin Thomas

Classifications

• G01N15/1436 Primary

  the optical arrangement forming an integrated apparatus with the sample container, e.g. a flow cell · CPC title

• G01N2015/1452

  Adjustment of focus; Alignment · CPC title

• G01N2015/1454

  using phase shift or interference, e.g. for improving contrast · CPC title

• G01N15/1459 Primary

  the analysis being performed on a sample stream · CPC title

• G01N2015/0046

  in gas, e.g. smoke · CPC title