For the characterization and Quality Assurance (QA) of prototype sensors produced for the Silicon Tracking System (STS) at the Compressed Baryonic Matter Experiment (CBM), a infrared pulsed Laser Testing System (LTS) has been developed. The main aim for the LTS is to scan and characterize the prototype sensors. These QA scans are intended to understand charge sharing in the interstrip region and investigate uniformity of sensor performance in the active area of prototype sensors. The prototype sensor CBM02 which has 256 strips with a pitch of 50 μm on each side has been investigated in the LTS [1]. The strips on the sensors are wire bonded to connectors on a board and readout via self-triggering n-XYTER prototype electronics. The goal for the LTS is to have automatized quality assurance tests in a controlled manner at several thousands positions across the sensor with focused infra-red laser light (σspotsize ≈ 15 μm). The duration (∼10 ns) and power (few mW) of the laser pulses are selected such that the absorption of the laser light in the 300 μm thick silicon sensors produces about 24 000 electrons,which is similar to the charge created by minimum ionizing particles (MIP) there.The wavelength of the laser was chosen to be 1060 nm because the absorption depth of infra-red light with this wavelength is of the order of the thickness of the silicon sensors [2].