Exploring the photoinduced dynamics of chiral states offers promising avenues for advanced control of condensed matter systems. Photoinduced or photoenhanced chirality in $1T\text{−}{\mathrm{TiSe}}_2$ has been suggested as a fascinating platform for optical manipulation of chiral states. However, the mechanisms underlying chirality training and its interplay with the charge density wave (CDW) phase remain elusive. Here, we use time-resolved x-ray diffraction (trXRD) with circularly polarized pump lasers to probe the photoinduced dynamics of chirality in $1T\text{−}{\mathrm{TiSe}}_2$. We observe a notable ($\sim 20\%$) difference in CDW intensity suppression between left and right circularly polarized pumps. Additionally, we reveal momentum-resolved circular dichroism arising from domains of different chirality, providing a direct link between CDW and chirality. An immediate increase in CDW correlation length upon laser pumping is detected, suggesting the photoinduced expansion of chiral domains. These results both advance the potential of light-driven chirality by elucidating the mechanism driving chirality manipulation in ${\mathrm{TiSe}}_2$, and they demonstrate that trXRD with circularly polarized pumps is an effective tool for chirality detection in condensed matter systems.

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• Charge density waves
• Charge dynamics
• Chirality
• Transition metal dichalcogenides
• Time-resolved light scattering spectroscopy
• X-ray diffraction