Broadly tunable microcomputer-controlled color-center laser for intracavity and extracavity sub-Doppler spectroscopy

A microcomputer-controlled color-center laser has been designed for broadband tunability and high-resolution sub-Doppler spectroscopy. The application of the programming language FORTH for controlling software provides high versatility and universal applicability to microcomputer-controlled laser spectrometers. Different tuning modes were optimized, allowing continuous-frequency scans over several wave numbers with a resolution of 15 MHz as well as high-resolution scans over 2 GHz with a step width of less than 100 kHz. Intracavity and extracavity detection techniques were tested on the nu-1 fundamental band of isothiocyanic acid and on the hydrofluoric acid P(4) vibration-rotation transition, indicating a resolution limit of less than 0.00001 per cm for the spectrometer.