Rapid-scanning computer-controlled tunable diode laser spectrometer.

A novel method for scanning and acquiring data from a tunable diode laser spectrometer is described. The beam from the diode is chopped with a tuning fork chopper, and the laser current is advanced during each dark cycle using a digital-to-analog converter. Spectra measured in this fashion show at least an order of magnitude improvement in signal-to-noise ratio over spectra measured in the conventional fashion using a lock-in amplifier, and signal drift is reduced. These improvements allow accurate line profiles to be measured and subtle changes in the diode emission modes to be monitored.