Open AccessActive fiber-based retroreflector providing phase-retracing anti-parallel laser beams for precision spectroscopy
Author(s) -
Axel Beyer,
Lothar Maisenbacher,
A. Matveev,
Randolf Pohl,
K. Yu. Khabarova,
Yue Chang,
Alexey Grinin,
Tobias P. Lamour,
Ting-Yun Shi,
Dylan C. Yost,
Thomas Udem,
Theodor W. Hänsch,
N. N. Kolachevsky
Publication year - 2016
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.017470
Subject(s) - retroreflector , optics , laser , spectroscopy , doppler effect , fiber laser , physics , materials science , quantum mechanics , astronomy
We present an active fiber-based retroreflector providing high quality phase-retracing anti-parallel Gaussian laser beams for precision spectroscopy of Doppler sensitive transitions. Our design is well-suited for a number of applications where implementing optical cavities is technically challenging and corner cubes fail to match the demanded requirements, most importantly retracing wavefronts and preservation of the laser polarization. To illustrate the performance of the system, we use it for spectroscopy of the 2S-4P transition in atomic hydrogen and demonstrate an average suppression of the first order Doppler shift to 4 parts in 10 6 of the full collinear shift. This high degree of cancellation combined with our cryogenic source of hydrogen atoms in the metastable 2S state is sufficient to enable determinations of the Rydberg constant and the proton charge radius with competitive uncertainties. Advantages over the usual Doppler cancellation based on corner cube type retroreflectors are discussed as well as an alternative method using a high finesse cavity.