公开(公告)号：US20210231495A1

公开(公告)日：2021-07-29

申请号：US17056225

申请日：2019-05-17

Applicant: THE REGENTS OF THE UNIVERSITY OF MICHIGAN

Inventor： Steven T. CUNDIFF ,  Chris SMALLWOOD ,  Eric MARTIN

IPC: G01J3/02 ,  G01J3/45 ,  G01J9/02

Abstract: A method is presented for determining path length fluctuations in an interferometer using a reference laser with an arbitrary frequency with respect to the measured light. The method includes: injecting reference light along signal paths of the interferometer; measuring interference between the reference light at an output of the interferometer; determining an optical phase difference between the reference light in the two signal paths of the interferometer by measuring intensity modulation of the interference between the reference light and subtracting an intended frequency modulation from the measured intensity modulation; accumulating an unwrapped phase difference between the reference light in the two signal paths of the interferometer, where the unwrapped phase difference is defined in relation to a reference; and determining path length fluctuation of light in the interferometer using the unwrapped phase difference.

公开(公告)号：US20180073856A1

公开(公告)日：2018-03-15

申请号：US15705511

申请日：2017-09-15

Applicant: The Regents of the University of Michigan

Inventor： Steven T. CUNDIFF ,  Bachana LOMSADZE

IPC: G01B9/02 ,  G01J3/45 ,  G01N21/31 ,  H01S3/13 ,  H04B10/50 ,  G01N21/25

CPC classification number: G01B9/02008 ,  G01J3/0262 ,  G01J3/0286 ,  G01J3/12 ,  G01J3/45 ,  G01J3/457 ,  G01J2003/1286 ,  G01N21/255 ,  G01N21/31 ,  G01N21/636 ,  G02F1/3536 ,  H01S3/0085 ,  H01S3/1112 ,  H01S3/13 ,  H01S3/1304 ,  H04B10/506

Abstract: Dual laser frequency combs can rapidly measure high resolution linear absorption spectra. However, one-dimensional linear techniques cannot distinguish the sources of resonances in a mixture of different analytes, nor separate inhomogeneous and homogeneous broadening. These limitations are overcome by acquiring high resolution multi-dimensional non-linear coherent spectra with frequency combs.