公开(公告)号：US11015975B2

公开(公告)日：2021-05-25

申请号：US16613614

申请日：2018-05-15

Applicant: The Trustees of Princeton University

Inventor： Lukasz Sterczewski ,  Jonas Westberg ,  Gerard Wysocki

IPC: G01J3/10 ,  G01J3/427

Abstract: Disclosed herein is an all-digital phase and timing correction procedure for coherent averaging in dual-comb and multiheterodyne spectroscopy—applicable to any dual-comb spectroscopy setup. It can account for large frequency/phase instabilities of the used sources, yielding a significant reduction of the noise pedestal and an increase in signal-to-noise ratio (SNR) of the radio frequency (RF) beat notes. This technique is computationally efficient and can be conveniently implemented either as a post-processing algorithm or in a real-time data acquisition and processing platform without the necessity of adding any additional optical elements to the dual-comb spectroscopy system. By implementing this technique, the performance of any comb- or comb-like-source-based DCS system with a sufficient degree of mutual coherence between the optical modes can be improved in terms of SNR and number of spectroscopically-usable RF beat notes. The described technique is compatible with a DC-centered RF spectrum, where the negative frequencies are folded to the positive domain to double the number of beat notes within the detector bandwidth. The technique enables coherent averaging over extended time-scales even for free-running combs, thus increasing the sensitivity of absorption and dispersion DCS measurements.

公开(公告)号：US11499867B2

公开(公告)日：2022-11-15

申请号：US17240172

申请日：2021-04-26

Applicant: The Trustees of Princeton University

Inventor： Lukasz Sterczewski ,  Jonas Westberg ,  Gerard Wysocki

IPC: G01J3/10 ,  G01J3/427

Abstract: Disclosed herein is an all-digital phase and timing correction procedure for coherent averaging in dual-comb and multiheterodyne spectroscopy—applicable to any dual-comb spectroscopy setup. It can account for large frequency/phase instabilities of the used sources, yielding a significant reduction of the noise pedestal and an increase in signal-to-noise ratio (SNR) of the radio frequency (RF) beat notes. This technique is computationally efficient and can be conveniently implemented either as a post-processing algorithm or in a real-time data acquisition and processing platform without the necessity of adding any additional optical elements to the dual-comb spectroscopy system. By implementing this technique, the performance of any comb- or comb-like-source-based DCS system with a sufficient degree of mutual coherence between the optical modes can be improved in terms of SNR and number of spectroscopically-usable RF beat notes. The described technique is compatible with a DC-centered RF spectrum, where the negative frequencies are folded to the positive domain to double the number of beat notes within the detector bandwidth. The technique enables coherent averaging over extended time-scales even for free-running combs, thus increasing the sensitivity of absorption and dispersion DCS measurements.

公开(公告)号：US20220233097A1

公开(公告)日：2022-07-28

申请号：US17609057

申请日：2020-05-06

Applicant: The Trustees of Princeton University

Inventor： Charles L. Patrick ,  Jonas Westberg ,  Gerard Wysocki

IPC: A61B5/083 ,  G01N21/61 ,  G01N33/00 ,  A61B5/00

Abstract: According to various embodiments, a sensing device for measuring oxygen concentration cycles in breath is disclosed. The sensing device includes a laser configured to emit light at an A-band of oxygen, a lens configured to collimate the light, and a multi-pass cell configured to contain a replaceable sample cell. The light passes through the multi-pass cell and is attenuated by oxygen in the sample cell. The sensing device further includes a photodetector configurated to convert the attenuated light into an electrical signal, and a lock-in amplifier or an equivalent processing circuit configured to determine oxygen concentration from the electrical signal.

公开(公告)号：US20210344167A1

公开(公告)日：2021-11-04

申请号：US17245242

申请日：2021-04-30

Applicant: The Trustees of Princeton University

Inventor： Chu C. Teng ,  Jonas Westberg ,  Gerard Wysocki

IPC: H01S5/0687 ,  H01S5/14

Abstract: According to various embodiments, a system for stabilizing operation of semiconductor laser frequency combs via optical feedback is disclosed. The system includes an external cavity having a beam-splitter, polarizer, and mirror or partially reflective element mounted on a translational stage. The external cavity and a laser facet of the semiconductor laser form an external optical resonator for coupling light to a laser cavity.