Experimental Chemical Kinetics Thermodynamics Division

Contact: <Jeffrey W. Hudgens>

Typical Ring-down Curves

Misaligned Cavity
Transverse Mode Beating observed in a misaligned cavity. This beating is also observed:
  • when the photomultiplier does not view the entire beam.
  • when the photomultiplier response function varies strongly across its face.

Aligned Cavity
CRDS Response exhibited by a Properly Aligned Cavity.
  • The small amplitude, high frequency beating arises from longitudinal cavity modes.
  • During experiments we average out these modulations by inserting a 50 MHz filter onto the analog input of our digital scope.
Picture of Apparatus

NEXT: Back to Home