Detection of photothermal deflection signals with conjugate masks.
A new detection technique for photothermal deflection spectroscopy and photoacoustic deflection spectroscopy is presented. The technique uses a pair of matched multiple slits placed in the path of the probe beam and oriented to block the probe light from the detector in the absence of a deflection signal. Significant improvement in the signal-to-noise ratio and in the frequency bandwidth compared with those available with current techniques is demonstrated.
Sharma
Anup
A
Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA. rgupta@uark.edu
Ycas
Gabriel
G
Alahmed
Zeyad
Z
Gupta
Rajendra
R