An integrated cavity output spectroscopic (ICOS) device includes a cavity and a mirror positioned at an output end of the cavity. The ICOS device also includes a first collection lens positioned between a detector and the mirror at the output end of the cavity, and a second collection lens positioned between the first collection lens and the detector. The ICOS device further includes an optical component configured to reduce skew of an optical signal output from the cavity, where the optical component is positioned between the mirror and the first collection lens.