Figure 1
From: Temperature and microwave near field imaging by thermo-elastic optical indicator microscopy
Measurement principle of TEOIM.
(a) Illustration of measurement principle of the TEOIM system. A circularly polarized incident light changes to an elliptically polarized state by the photoelastic effect of the optical indicator (OI) caused by a thermal stress. The thermal stress comes from the electromagnetic heating caused by interaction between the OI-material and electromagnetic wave radiated from a device under test. (b) Illustration of experimental setup of TEOIM. The incident light is modulated to be circularly polarized (left handed polarized: LCP; right handed polarized: RCP) states by the liquid crystal modulator (LCM) and a linear sheet polarizer. The polarization state of the reflected light from the OI is determined by measuring the light intensity passing through the analyzer aligned at 0°and 45°, where the light intensity is measured by charge coupled device (CCD) image sensor.
