	US 12,276,599 B2
	Temporal magnification spectrometer and performing spectroscopic temporal magnification
David Francis Plusquellic, Boulder, CO (US); and Jasper Rose Stroud, Boulder, CO (US)
Assigned to GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE, Gaithersburg, MD (US)
Filed by Government of the United States of America, as represented by the Secretary of Commerce, Gaithersburg, MD (US)
Filed on May 2, 2023, as Appl. No. 18/142,365.
Claims priority of provisional application 63/337,201, filed on May 2, 2022.
Prior Publication US 2023/0349821 A1, Nov. 2, 2023
Int. Cl. G01N 21/31 (2006.01)

CPC G01N 21/31 (2013.01) [G01N 2201/06113 (2013.01)]

20 Claims

1. A temporal magnification spectrometer for performing spectroscopic temporal magnification, the temporal magnification spectrometer comprising:

a dual-chirp comb source that produces optical carrier laser light;

a signal leg in optical communication with the dual-chirp comb source and that:

receives the optical carrier laser light from the dual-chirp comb source;

produces a signal comb comprising a series of signal linearly chirped waveforms characterized by a chirp duration τ_cpand a signal frequency range Δf_SIG; and

interacts the signal comb with a sample over the signal frequency range Δf_SIGto produce a transmitted signal comb;

a local oscillator leg in optical communication with the dual-chirp comb source and that:

receives the optical carrier laser light from the dual-chirp comb source; and

produces a local oscillator comb comprising a series of local oscillator linearly chirped waveforms characterized by the chirp duration τ_cpand a local oscillator frequency range Δf_LO, such that the local oscillator frequency range Δf_LOis different than the signal frequency range Δf_SIG;

an optical detector in optical communication with the signal leg and the local oscillator leg and that:

receives the transmitted signal comb from the signal leg;

receives the local oscillator comb from the local oscillator leg; and

produces an RF domain signal from mixing the transmitted signal comb and the local oscillator comb; and

a temporal magnification analyzer in communication with the optical detector and that:

receives the RF domain signal from the optical detector;

subjects the RF domain signal to a Fourier transform to produce an RF comb comprising a series of RF linearly chirped waveforms;

samples the RF comb to produce sampled RF comb lines from the RF comb;

normalizes the magnitude and phase response of the sampled RF comb lines and produces temporally magnified sample frequency domain data from the sampled RF comb lines;

subjects the sampled RF comb lines to an Inverse Fourier transform to produce intermediate sample temporal data; and

normalizes the magnitude and phase response of the intermediate sample temporal data to produce a steady-state sample spectral response from the intermediate sample temporal data.