This study proposes a simple method for measuring two-dimensional temperature distributions. Using the significant
phase difference between p- and s-polarizations of the reflected light of a surface plasmon resonance (SPR) detector, the
variation in the phase difference, which is caused by a variation in the temperature, can be accurately measured by
phase-shifting interferometry. Then, by substituting the phase distribution into special derived equation, the temperature distribution can be determined. In order to show the feasibility of this method, different temperature distributions were
measured. The measurement resolution is about 0.186°C. Due to the introduced common-path configuration and the high-sensitivity characteristic of surface plasmon resonance, this method should have merits of easy operation, high sensitivity, high accuracy and rapidly measurement.