Manufacturable Q-VCSELs for quantum sensors

In this paper, we report on the development and electro-optical characterization of manufacturable, quantum-optimized 795-nm vertical-cavity surface-emitting lasers (VCSELs) for rubidium (Rb) quantum sensors, including chip-scale atomic clocks (CSAC) and optically-pumped magnetometers (OPM). Operation at 795 nm (Rb D1) is constrained by increased internal loss/absorption, polarization instability, and stringent requirements on spectral purity. To address these challenges at the component level, we combine advanced epitaxial design with chip-layout engineering to improve mode discrimination, polarization robustness, and high-temperature efficiency. The resulting devices sustain stable single-transverse-mode emission and linear polarization from 20–80 °C, achieving side-mode suppression ratio (SMSR) >30 dB and polarization extinction ratio (PER) >20 dB. Compared with legacy 795-nm VCSEL sources, the demonstrated lasers exhibit reduced threshold current (0.5 mW/mA), enabling >1 mW of single-mode, single-polarization output power in chip-scale form factors. We further measure quantum-relevant performance, including ~30 MHz linewidth and relative intensity noise below −130 dB/Hz (measurement conditions specified), supporting low-SWaP system integration for scalable Rb-based sensing networks.