Open AccessIntensity noise characteristics of intracavity contacted VCSELs with rhomboidal oxide current aperture for the magnetometric sensor with Cs133 vapor cell used in magnetoencephalography
Author(s) -
M. A. Bobrov,
S. A. Blokhin,
N. A. Maleev,
A. A. Blokhin,
A. P. Vasyl’ev,
A. G. Kuzmenkov,
V. M. Ustinov,
I. I. Novikov,
L. Ya. Karachinskiĭ
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2103/1/012182
Subject(s) - relative intensity noise , materials science , laser linewidth , optics , optoelectronics , vertical cavity surface emitting laser , laser , orthogonal polarization spectral imaging , semiconductor laser theory , physics , diode
We demonstrate noise characterization of novel 894.4 nm vertical-cavity surface emitting lasers with intracavity contacts and a rhomboidal oxide current aperture (IC-VCSELs), dedicated to 133 Cs D1 line compact optically pumped atomic magnetometers (OPM). The laser relative intensity noise, measured to be -139 dB/Hz at 10 kHz frequency in 1 Hz bandwidth for a laser optical power of 0.8 mW, is decreased with optical power growth. The IC-VCSELs polarization-resolved relative intensity noise is 143 dB/Hz at 10 kHz frequency in 1 Hz bandwidth for 0.8 mW. The emission linewidth of the VCSEL is about 55 MHz. The IC-VCSEL parameters are determined, such as emission linewidth ~ 50-60 MHz, optical power ~ 0.5-1.0 mW, at which the polarization-resolved RIN becomes close to the RIN, which makes it possible to use these lasers in various OPM Mz and Mx schemes. The ultimate sensitivity of OPM was estimated by the ratio of the magnetic resonance to the signal to noise level. It is shown that a OPM based on the IC-VCSELs, assuming magnetic resonance FWHM ~ 1 kHz, can achieve a shot noise-limited sensitivity around 20 fT in 1 Hz bandwidth without any polarization improvements by polarizer or polarization beam splitter cube (PBC). Developed IC-VCSELs is acceptable for use in compact OPM for magnetoencephalography.