The high sensitivity absorption spectrum of ozone (18O3 and 16O3) near 7800 cm−1: Identification of the 3A2(0 0 0)-X(1 1 0) hot band superimposed to very weak vibrational bands

► The spectrum of ozone (16O3 and 18O3) has been recorded by CRDS near 7800 cm−1. ► Unexpected broad absorption features were detected in the 18O3 spectrum. ► They are assigned to the 3A2(0 0 0)-X(1 1 0) hot band. ► Two very weak vibrational cold bands of 18O3 were also evidenced. ► They are the highest vibrational bands of ozone detected so far by absorption.