Apparatus and method for calibrating measuring instruments

Patent metadata

Field	Value
Publication number	US-10677652-B2
Application number	US-201716334944-A
Country	US
Kind code	B2
Filing date	Oct 17, 2017
Priority date	Oct 17, 2016
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A method and apparatus is provided for implementing a parametric down-conversion (PDC)-based calibration comprising calibrating a measuring instrument; disposing a pinhole at a position of a light-emitting sample for which the measuring instrument needs to be calibrated; irradiating a nonlinear crystal with a light source; setting the nonlinear crystal by ensuring a phase-matching wavelength of the nonlinear crystal is set at one boundary of a desired bandwidth; acquiring one or more PDC spectrums by the measuring instrument; obtaining peak values and their corresponding wavelengths from each acquired spectrum; and obtaining a response function based on the peak values and corresponding wavelengths.

First claim

What is claimed is:

1. An apparatus for implementing a parametric down-conversion (PDC)-based calibration comprising:
a light source;
a nonlinear crystal irradiated by the light source and configured to produce down-converted light comprising pairs of photons;
an optical component in line with the nonlinear crystal for suppressing the light source and collecting the down-converted light from the nonlinear crystal;
a collimating optical component for receiving the down-converted light from the nonlinear crystal;
a polarizer for adjusting the polarization of the down-converted light; and
a regulator for adjusting an angular width of the radiation of the down-converted light,
wherein the pairs of photons in the down-converted light travel from the nonlinear crystal along a single optical pathway comprising the optical component, the collimating optical component, the polarizer, and the regulator, for measuring a ratio between a measured spectrum and an expected spectrum based on peak values and corresponding wavelengths.

2. The apparatus of claim 1 , wherein the nonlinear crystal is adjustable to alter a phase-matching condition of the nonlinear crystal.

3. The apparatus of claim 2 , wherein the adjustment is made by rotating the nonlinear crystal.

4. The apparatus of claim 2 , wherein the adjustment is made by changing the temperature of the nonlinear crystal.

5. The apparatus of claim 1 , wherein the optical component is a dichroic mirror.

6. The apparatus of claim 1 , wherein the collimating optical component is a concave mirror or an achromatic lens.

7. The apparatus of claim 1 , wherein the light source is a laser.

8. The apparatus of claim 1 , wherein the parametric down-conversion (PDC)-based calibration is performed on a measuring instrument.

9. The apparatus of claim 8 , wherein the measuring instrument is a spectrometer or a spectrophotometer.

10. A system for calibrating a measuring instrument comprising:
a light source;
a nonlinear crystal irradiated by the light source and configured to produce down-converted light comprising pairs of photons;
an optical component in line with the nonlinear crystal for suppressing the light source and collecting the down-converted light from the nonlinear crystal;
a collimating optical component for receiving the down-converted light from the nonlinear crystal;
a polarizer for adjusting the polarization of the down-converted light;
a regulator for adjusting an angular width of the radiation of the down-converted light; and
an optical system for imaging the radiation from the regulator to the measuring instrument,
wherein the pairs of photons in the down-converted light travel from the nonlinear crystal to the measuring instrument along a single optical pathway comprising the optical component, the collimating optical component, the polarizer, the regulator, and the optical system, for measuring a ratio between a measured spectrum and an expected spectrum based on peak values and corresponding wavelengths.

11. The system of claim 10 , wherein the nonlinear crystal is adjustable to alter a phase-matching condition of the nonlinear crystal.

12. The system of claim 11 , wherein the adjustment is made by rotating the nonlinear crystal.

13. The system of claim 11 , wherein the adjustment is made by changing the temperature of the nonlinear crystal.

14. The system of claim 10 , wherein the collimating optical component is a concave mirror or an achromatic lens.

15. The system of claim 10 , wherein the optical component is a dichroic mirror.

16. The system of claim 10 , wherein the light source is a laser.

17. The system of claim 10 , wherein the measuring instrument is a spectrometer or a spectrophotometer.

18. The system of claim 10 , wherein the regulator is disposed in a far field of the nonlinear crystal, by use of the collimating optical component.

19. The system of claim 18 , wherein the regulator is a small aperture.

20. The system of claim 19 , wherein the small aperture is a pinhole.

21. A method for implementing a parametric down-conversion (PDC)-based calibration comprising:
calibrating a measuring instrument;
disposing a pinhole at a position of a light-emitting sample for which the measuring instrument needs to be calibrated;
irradiating a nonlinear crystal with a light source, the nonlinear crystal configured to produce down-converted light comprising pairs of photons that travel along a single optical pathway to the measuring instrument;
setting the nonlinear crystal by ensuring a phase-matching wavelength of the nonlinear crystal is set at one boundary of a desired bandwidth;
acquiring one or more PDC spectra spectrums of the down-converted light by the measuring instrument;
obtaining peak values and their corresponding wavelengths from each acquired spectrum; and
obtaining a response function as a ratio between a measured spectrum and an expected spectrum based on the peak values and corresponding wavelengths.

22. The method of claim 21 , wherein the measuring instrument is a spectrometer or a spectrophotometer.

23. The method of claim 21 , wherein the light source is a pump laser.

24. The method of claim 21 , wherein setting the nonlinear crystal comprises:
adjusting a phase-matching condition of the nonlinear crystal.

25. The method of claim 24 , wherein adjusting the phase-matching condition comprises:
rotating the nonlinear crystal.

26. The method of claim 24 , wherein adjusting the phase-matching condition comprises:
changing the temperature of the nonlinear crystal.

27. The method of claim 21 , wherein background noise is subtracted when calibrating the measuring instrument.

28. The method of claim 21 , wherein a curve-fitting algorithm is applied if the spectrum is noisy when peak values are obtained.

29. The method of claim 21 , wherein the response function is calculated by measuring a spectrum of the light source and dividing the spectrum of the light source by a known reference output.

Assignees

• Univ Ottawa
• Max Planck Gesellschaft
• Univ Friedrich Alexander Er

Inventors

• Lemieux Samuel
• Manceau Mathieu
• Boyd Robert W
• Leuchs Gerd
• Chekhova Maria V

Classifications

• G01J3/0208

  using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction · CPC title

• G01J2003/1861

  Transmission gratings · CPC title

• G01J3/0224

  using polarising or depolarising elements · CPC title

• G01J3/0297 Primary

  Constructional arrangements for removing other types of optical noise or for performing calibration · CPC title

• G01J3/2803

  using photoelectric array detector · CPC title