Specular integrating tube for scattered-light spectroscopy.

A scattered-light spectroscopy system for collecting light scattered from a sample, e.g. Raman-scattered light, to produce a spectrum of the sample, includes a cylindrical cell for holding the sample that is transparent and coated on either its inside surface or outside surface with a reflective coating, e.g. aluminum. The reflective coating has an opening for aligning with an aperture in a spectrometer for receiving the sample-scattered light. Light from a source such as a laser illuminates the sample to produce a scattered light having a first part received directly at the opening and a second part reflected by the reflective coating one or more times prior to arrival at the opening, thereby adding to the total scattered light entering the aperture of the spectrometer to improve its collection efficiency.