The emergence of biomagnetism imaging has led to the development of ultrasensitive and compact spin-exchange relaxation-free(SERF)atomic magnetometers that promise high-resolution magnetocardiography(MCG)and magnetoen...The emergence of biomagnetism imaging has led to the development of ultrasensitive and compact spin-exchange relaxation-free(SERF)atomic magnetometers that promise high-resolution magnetocardiography(MCG)and magnetoencephalography(MEG).However,conventional optical components are not compatible with nanofabrication processes that enable the integration of atomic magnetometers on chips,especially for elliptically polarized laserpumped SERF magnetometers with bulky optical systems.In this study,an elliptical-polarization pumping beam(at 795 nm)is achieved through a single-piece metasurface,which results in an SERF magnetometer with a high sensitivity reaching 10.61 fT/Hz1/2 by utilizing a 87Rb vapor cell with a 3mm inner diameter.To achieve the optimum theoretical polarization,our design combines a computer-assisted optimization algorithm with an emerging metasurface design process.The metasurface is fabricated with 550 nm thick silicon-rich silicon nitride on a 2×2 cm^(2)SiO_(2)substrate and features a 22.17°ellipticity angle(a deviation from the target polarization of less than 2%)and more than 80%transmittance.This study provides a feasible approach for on-chip polarization control of future allintegrated atomic magnetometers,which will further pave the way for high-resolution biomagnetism imaging and portable atomic sensing applications.展开更多
基金supported by the National Science Fund for Outstanding Young Scholars(37127701)the National Natural Science Foundation of China(77051001)the Innovation Program for Quantum Science and Technology(0300503).
文摘The emergence of biomagnetism imaging has led to the development of ultrasensitive and compact spin-exchange relaxation-free(SERF)atomic magnetometers that promise high-resolution magnetocardiography(MCG)and magnetoencephalography(MEG).However,conventional optical components are not compatible with nanofabrication processes that enable the integration of atomic magnetometers on chips,especially for elliptically polarized laserpumped SERF magnetometers with bulky optical systems.In this study,an elliptical-polarization pumping beam(at 795 nm)is achieved through a single-piece metasurface,which results in an SERF magnetometer with a high sensitivity reaching 10.61 fT/Hz1/2 by utilizing a 87Rb vapor cell with a 3mm inner diameter.To achieve the optimum theoretical polarization,our design combines a computer-assisted optimization algorithm with an emerging metasurface design process.The metasurface is fabricated with 550 nm thick silicon-rich silicon nitride on a 2×2 cm^(2)SiO_(2)substrate and features a 22.17°ellipticity angle(a deviation from the target polarization of less than 2%)and more than 80%transmittance.This study provides a feasible approach for on-chip polarization control of future allintegrated atomic magnetometers,which will further pave the way for high-resolution biomagnetism imaging and portable atomic sensing applications.
