Time Resolved Pulsed Photoacoustic Spectroscopy of formaldehyde Molecules at 266 nm

We have reported the time resolved pulsed Photoacoustic (PA) spectrum of formaldehyde molecules (CH2O)  We have introduced newly designed PA resonance   (L2=6.5cm, R2=0.75 cm) coupled with special filter.  The 4th harmonic i.e. 266nm (UV) pulses obtained from Q-switched Nd: YAG laser having 7 ns pulse width is used to excite the resonant modes of the cavity. We have recorded the Photoacoustic spectrum of formaldehyde in time and frequency domains. In addition, we have studied other important factors such as minimum detection limit, incident laser energy,  effect of sample pressure, Acquiescing time and the efficiency of PA cells with different excited modes.