Optical reflectors for spectrometer gas cells

A spectrometer cell can include a spacer, at least one end cap, and at least one mirror with a reflective surface. The end cap can be positioned proximate to a first contact end of the spacer such that the end cap and spacer at least partially enclose an internal volume of the spectrometer cell. The mirror can be secured in place by a mechanical attachment that may include attachment materials that are chemically inert to at least one reactive gas compound, be thermally stable above at least 120 °C, and be capable of holding an optical axis of the reflective surface in a fixed orientation relative to other components of the spectrometer cell and or a spectrometer device that comprises the spectrometer cell. The mirror can optionally be constructed of a material such as stainless steel, copper, aluminum, alumino-silicate, ceramic, or the like. Related methods, articles of manufacture, systems, etc. are described.