Abstract: An automatic personal computer-based, rapid calibration system for tunable, narrowband lasers is achieved, detecting the LIF (Laser Induced Fluorescence) spectrum of a suitable known medium in a reference cell, which is also stored as a database in the PC to compute a functional relationship between the wavelength-shifting actuator in the laser and the emitted laser wavelength. The PC is either connected to the LIF spectrum-detecting circuit and the laser interface. Substances (media) used for reference have to exhibit at least two distinct electronic absorption lines within the tunability range of the laser. By comparing the measured and the stored LIF spectrum of the reference medium, the spectral properties of the laser are calculated automatically.