Modeling Thermal Lensing in Soy Sauce*

Interesting thermal lensing effects in ordinary soy sauce have been demonstrated in previous experiments in the form of rings of the concentric circular intensity profiles. Here we produce more quantitative results for thermal lens produced by this substance. More specifically we are concerned with the absorbance of the medium and with defining the lensing needed to produce the observed image. This process utilizes a vertical setup, two photodiodes, two pick-off glasses, a ccd camera, a handheld green laser, and a thermistor. The absorbance is measured by comparing the radiant flux of the light source before and after interacting with the medium. The lens produced is measured by using imagery from the camera to try to determine the intensity of the light rings. We recreate the absorbance and final image in a mathematical model.