Miniature IF-ECDL based laser system with 14 Hz integral linewidth

This is the authors' abstract. We don't add key points for this paper.

Narrow-linewidth lasers are fundamental for high-precision applications in metrology, timekeeping, and quantum system manipulation. Conventional approaches typically rely on bulk-optical lasers stabilized to high-finesse reference cavities, resulting in large system size and limited environmental adaptability, which restrict their practical deployment. In this work, we present an interference-filter external cavity diode laser (IF-ECDL) with a volume of 3.3 mL, stabilized to a whispering gallery mode (WGM) resonator fabricated from M g F 2 , achieving a 1/ π -integral linewidth of 13.8 Hz, and an instability of 5.9 × 10 − 12 at 0.1 s. This work demonstrates a compact, low-noise optical-frequency source based on microresonator stabilization, providing a promising route toward portable precision metrology, optical atomic clocks, and quantum sensing applications.