A two-color dual-comb system for time-resolved measurements of ultrafast magnetization dynamics using triggerless asynchronous optical sampling.

This article focuses on the development and application of a two-color Er-doped fiber (EDF)-laser-based dual-comb system for triggerless asynchronous optical sampling (ASOPS) pump–probe measurements of ultrafast demagnetization and spin precession in magnetic materials. The system achieves high temporal resolution and long probe times by fully stabilizing the frequencies of two frequency-comb light sources, enabling data acquisition without electrical trigger signals. Using wavelength conversion and amplification techniques, the pump and probe pulses are generated at approximately 1030 nm and 775 nm, respectively, allowing precise time-resolved magneto-optical Kerr effect (TR-MOKE) measurements on a permalloy thin film. Experimental results demonstrate ultrafast spin dynamics consistent with theoretical predictions, highlighting the system's potential for rapid and high-resolution characterization of magnetization dynamics and spin-wave phenomena in magnetic materials.