Application of VCSEL in Bio-Sensing Atomic Magnetometers

Abstract

Recent years have seen rapid development of chip-scale atomic devices due to their great potential in the field of biomedical imaging, namely chip-scale atomic magnetometers that enable high resolution magnetocardiography (MCG) and magnetoencephalography (MEG). For atomic devices of this kind, vertical cavity surface emitting lasers (VCSELs) have become the most crucial components as integrated pumping sources, which are attracting growing interest. In this paper, the application of VCSELs in chip-scale atomic devices are reviewed, where VCSELs are integrated in various atomic bio-sensing devices with different operating environments. Secondly, the mode and polarization control of VCSELs in the specific applications are reviewed with their pros and cons discussed. In addition, various packaging of VCSEL based on different atomic devices in pursuit of miniaturization and precision measurement are reviewed and discussed. Finally, the VCSEL-based chip-scale atomic magnetometers utilized for cardiac and brain magnetometry are reviewed in detail. Nowadays, biosensors with chip integration, low power consumption, and high sensitivity are undergoing rapid industrialization, due to the growing market of medical instrumentation and portable health monitoring. It is promising that VCSEL-integrated chip-scale atomic biosensors as featured applications of this kind may experience extensive development in the near future.

Polarization multiplexing in VCSEL-arrays

“…Switching between these polarization states becomes possible by addressable VCSEL sub-arrays with 90°-rotated gratings, whereas the level of polarization extinction, threshold, slope or output power stays comparable for each channel [12], [13]. This technology can be applied on any kind of VCSEL configuration (transversal single-mode or multi-mode & small or large arrays) to gain additional noise and polarization performance benefits [14][15][16][17]. Surpassing standard consumer sensing qualification tests is already demonstrated for single-mode / multi-mode chips in various configurations.…”