Saturated absorption frequency stabilization of VCSELs based on high-temperature operation

Quantum precision measurement requires pump light with high stability and strict wavelength constrains to polarize atoms. High-temperature vertical-cavity surface-emitting lasers (VCSELs) have become a reliable pump light source due to their inherent wavelength stability and robust performance at elevated temperatures. To address the issue of weak spatial optoelectronic signals, a frequency-stabilized optical path was designed by analyzing beam quality, and MATLAB software was used to conduct a joint simulation of the motion of the alkali metal vapor cell and the linewidth of the VCSEL. This simulation helped to determine the appropriate operating temperature, enabling the extraction of frequency error signals under the condition of the limited spatial optical power, while controlling the frequency offset caused by the Doppler effect. To ensure high-quality extraction of the error signals generated under limited power, the simulation results of seven error signal extraction schemes were compared. Through experimental testing of signal quality, the sinusoidal phase-locked amplification method was ultimately selected as the extraction approach. Finally, a laser frequency stabilization system was constructed based on a high-temperature operating VCSEL, which had a natural wavelength jitter of 0.4 nm, to an output power of 1.3 mW with a lasing wavelength of 780 nm. It achieved a spatial light output with a wavelength stability of 0.0002 nm and a frequency stability of 78.56 MHz, providing a practical and feasible operational solution for the miniaturization of quantum precision measurement devices.