An optical measurement device calibration tool includes an optical probe suitable for calibrating various optical imaging devices, for example, low coherence reflectometers and optical coherence tomography devices. In a preferred embodiment the calibration tool comprises a container containing a calibration substance with stable optical scattering and absorption properties. The calibration substance includes a gel, paste or grease substance and is covered a protective seal, which is at least partially transparent providing optical contact between the optical probe and the calibration substance. The protective seal is covered with a viscous complementary material. Another protective seal made at least partially removable is placed above the viscous complementary material and may serve as a cover for the container. The calibration tool maintains the advantages of calibration tools using liquids and solid states as calibration substance and is more cost-effective and more convenient for calibrating optical measuring devices such as in medical applications.