NEWTON, N.J., Oct. 9, 2013 — Thorlabs has extended its broadband sources into the IR spectral range with the addition of the SLS201 and SLS202, two fiber-coupled tungsten light sources for chemical, medical and biological spectral analysis. The sources come in two versions, both featuring a constant-intensity blackbody radiation spectrum that ranges from either 300 to 2600 nm (tungsten halogen) or from 450 to 5500 nm (tungsten). They have a built-in removable filter holder, allowing the placement of standard 1-in.-diameter spectral filters into the light path. The holder also can function as a sample holder for materials analysis. The internal feedback system of both models stabilizes the light-power variation to within 0.05% and reduces the power drift to 0.01% per hour compared with the standard 0.3% per hour typical of other tungsten-halogen light sources. This evenness allows the user to work for longer periods before needing to take a reference measurement.