Spectrometer with active beam steering

An apparatus comprising:

• a light source configured to emit a beam into a channel comprising an absorbing medium, wherein the light source is a tunable diode laser;
• at least one detector positioned to detect at least a portion of the beam emitted by the tunable diode laser, wherein the tunable diode laser and the detector are positioned on opposing sides of the channel in an open path configuration;
• at least one actuation element configured to selectively cause the beam emitted by the tunable diode laser to be steered;
• and
• a controller coupled to the at least one actuation element, the controller configured to:
• determine that a path of the beam should be steered based on at least one of an intensity level and a position of the beam detected by the at least one detector;
• identify a divergence of the path of the beam and/or optical diffraction and/or an interference along the path of the beam;
• and cause the at least one actuation element to steer the beam to adjust the position and/or an angle of the beam to correct the divergence and/or the optical diffraction and/or the interference along the path of the beam in response to the position and/or an angle of the beam that is detected by the detector.