摘要 |
A method apparatus for sensing gases using a semiconductor diode laser spectrometer, the method comprising: introducing a sample gas into a non-resonant optical cell ( 17 ); applying a step function electrical pulse ( 19 ) to a semiconductor diode laser ( 20 ) to cause the laser ( 20 ) to output a continuous wavelength chirp for injecting ( 16 a) into the optical cell ( 17 ); injecting ( 16 a) the wavelength chirp into the optical cell ( 17 ); using the wavelength variation provided by the wavelength chirp as a wavelength scan, and detecting ( 23 ) light emitted from the cell ( 17 ), wherein a chirp rate is selected to substantially prevent light interference occurring in the optical cell ( 17 ). |