MastCam-Z, ChemCam/SuperCam and MAHLI are optical systems and ChemCam includes a telescope and a pulsed laser, but the spectrometer is separated by a connecting optical fiber; presumably to keep it tucked away some place warm.
How cold do all these systems get out there at the ends of various rover appendages? Are they insulated and heated, or like most space probes have been for a half-century simply designed to withstand large temperature swings?
From this answer:
...(Perseverance) simply cannot maintain a decent temperature except for the most essential of systems.