This study investigates the effect of vapor content on the collapse of laser-induced cavitation bubbles in aqueous ammonia. Experiments with varying ammonia concentrations show that higher vapor pressure within the bubble reduces energy dissipation and leads to a more spherical collapse. The results suggest that vapor inside collapsing bubbles is compressed, consistent with previous studies on single bubble sonoluminescence. These findings highlight the significant role of vapor compression in bubble dynamics and provide insights into energy exchanges between bubbles and their surroundings. The study also reveals that the energy dissipation mechanisms during bubble collapse differ from classical models, indicating that shock wave emission is not the dominant dissipation mechanism. The results emphasize the importance of vapor content in influencing bubble behavior and energy dissipation, with implications for engineering and biomedical applications. The study also addresses the role of phase change and non-spherical deformations in bubble dynamics, showing that these factors can significantly affect the collapse process. The findings contribute to a better understanding of cavitation bubbles and their behavior in various conditions, with potential applications in fields such as sonochemistry and biomedical technologies. The study also highlights the need for more precise numerical models that account for phase transitions and non-spherical bubble collapses.This study investigates the effect of vapor content on the collapse of laser-induced cavitation bubbles in aqueous ammonia. Experiments with varying ammonia concentrations show that higher vapor pressure within the bubble reduces energy dissipation and leads to a more spherical collapse. The results suggest that vapor inside collapsing bubbles is compressed, consistent with previous studies on single bubble sonoluminescence. These findings highlight the significant role of vapor compression in bubble dynamics and provide insights into energy exchanges between bubbles and their surroundings. The study also reveals that the energy dissipation mechanisms during bubble collapse differ from classical models, indicating that shock wave emission is not the dominant dissipation mechanism. The results emphasize the importance of vapor content in influencing bubble behavior and energy dissipation, with implications for engineering and biomedical applications. The study also addresses the role of phase change and non-spherical deformations in bubble dynamics, showing that these factors can significantly affect the collapse process. The findings contribute to a better understanding of cavitation bubbles and their behavior in various conditions, with potential applications in fields such as sonochemistry and biomedical technologies. The study also highlights the need for more precise numerical models that account for phase transitions and non-spherical bubble collapses.