Work

10-fs-level laser-to-RF timing jitter of a directly diode-pumped Ti:sapphire oscillator

Year: 2026

Type: article

Abstract: We demonstrate 10-fs-level laser-to-RF synchronization of a directly diode-pumped Kerr-lens mode-locked Ti:sapphire oscillator operating at 79.333 MHz, the 36th subharmonic of the PAL-XFEL 2.856-GHz RF reference. Pump-dependent free-running phase-noise measurements were used to identify a low-jitter operating condition. The oscillator delivered 117 mW of average output power, 44-fs pulses, an 18-nm optical bandwidth, and 0.5% RMS power fluctuations over 10 h without active pump-power stabilization. An in-loop balanced optical-microwave phase detector (BOMPD) provided cavity-length feedback, while an independent out-of-loop BOMPD measured a residual laser-to-RF timing jitter of approximately 10 fs RMS over 1 Hz-1 MHz. The independently measured background-noise-equivalent timing jitter was 3 fs RMS over the same bandwidth, indicating that the residual measurement was not dominated by measurement-system background noise. These results demonstrate the feasibility of accelerator-compatible, 10-fs-level synchronization using a directly diode-pumped Ti:sapphire oscillator.

Source: Optics Express

DOI: 10.1364/oe.614433

Authors: Seong-Hoon Kwon, Seonghoon Jung, Chang-ki Min

Institutions: Pohang University of Science and Technology, Pohang Accelerator Laboratory

Language: English

Topic: Laser-Matter Interactions and Applications

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funder: National Research Foundation of Korea