Granted Patent B2

US 12,517,039 · App. 17/944,965 · Granted Jan 6, 2026

Inventors: Yuping Huang (Norwood, NJ); Yong Meng Sua (Fort Lee, NJ); Jiuyi Zhang (Palisades Park, NJ); Jiayang Chen (Jersey City, NJ); Jeevanandha Ramanathan (Jersey City, NJ)

Assignee: The Trustees of the Stevens Institute of Technology

G01N21/31G01N33/0027G02B6/29338G02B6/29383G02B6/29395G01N2201/06113G01N2201/08

Abstract

Claims (21)

1 . A method for single-photon spectroscopy, comprising the steps of:

collecting photons using a beam expander into a collimated single-mode fiber;

letting said photons pass through a long-pass filter to create long-pass filtered photons and to eliminate photons from other bands;

filtering said long-pass filtered photons with a band-pass filter to define a spectral window adapted to pick a single gas absorption line-shape and obtain filtered light;

utilizing a fiber polarizer to select said filtered light along a certain polarization, thereby producing filtered and polarized light;

splitting said filtered and polarized light into a first portion of light and a second portion of light;

routing said first portion of light through a signal photon counting channel comprising a calibrated micro-ring resonator filter and a field-programmable-gate-array;

tuning the resonance of said micro-ring resonator filter to sweep through said spectral window;

using said field-programmable-gate-array to tune a center wavelength of said micro-ring resonator filter;

acquiring first photon counting data from said signal photon counting channel following the performance of said tuning and using steps;

directly after the performance of said splitting step, coupling said second portion of light into a bypass photon counting channel;

detecting photons at a close-by wavelength in said bypass photon counting channel, said close-by wavelength having a center spectrum 1 nm or less away from said center wavelength of said single gas absorption line-shape, thereby obtaining second photon counting data; and

producing synchronized photon counting data from said first photon counting data and said second photon counting data.

2 . The method of claim 1 , wherein said collecting step is performed on solar photons.

3 . The method of claim 1 , wherein said collecting step is performed on photons created by a laser source illuminating on a target through Raman scattering, fluorescence, or Brillouin scattering optical processes.

4 . The method of claim 1 , wherein said micro-ring resonator filter is an add-drop micro-ring resonator etched on lithium niobate on insulator.

5 . The method of claim 4 , wherein said micro-ring resonator filter includes an integrated metal heater.

6 . The method of claim 1 , wherein said splitting step is performed with a 99:1 coupler.

7 . The method of claim 1 , wherein said acquiring step is conducted simultaneously with said detecting step.

8 . The method of claim 1 , wherein said spectral window is adequately narrow to measure absorption with high resolution during said tuning step.

9 . The method of claim 1 , wherein said single gas absorption line shape corresponds to CO 2 .

Continuity (2)

References Cited (93)