The control of the transient Diesel engine emissions requires their fast and accurate measurement, as close as possible to the outlet valve in order to limit mixing phenomena. Suitable devices are available for some exhaust components, but, unfortunately, not for soot, a solid component transported by the exhaust gas, but not dissolved in it. Against this background, in a previous work, an in-situ, full stream Laser Induced Incandescence (LII) probe has been proposed, which can be mounted upstream of the turbine of a production engine and delivers very fast responses. As a way to retain the advantages, a new concept has been developed which retains laser output and photomultiplier input in a compact housing. The captured intensity is calibrated by steady state points and validated against a standard commercial device, AVL Opacimeter. Afterwards, the steady and transient performance is shown and compared with Opacimeter. At last, the paper presents the higher speed and the corresponding richness of information on raw soot emissions.