Improvement in the precision of a high-resolution spectrometer based on diode lasers by stabilization of reference-line scanning cycles

A description is given of a method for increasing the precision of recording high-resolution spectra with an infrared spectrometer based on diode lasers. A distinguishing feature of the method is the use, in the control system, of an additional feedback circuit in which accidental drifts of the emission frequency of a pulseperiodic laser (measured relative to a reference absorption line) are converted into changes of the continuous component of the pump current. The maximum attainable precision is limited by the stability of the parameters of the signal processing devices in the feedback circuit and it is estimated to be 10^–5 cm^–1 relative to the reference line in use.