The accuracy of infrared temperature estimation can degrade significant for enclosed objects with reflective surfaces.
This paper describes a basic model of the incident radiation on a FPA sensor element considering a target
object, surrounding environment, surface temperatures, surface emissivity/reflection and optics. The model is
used to characterize the direct (one color method) temperature estimation error as a function of reflection, wavelength,
target temperatures and the environment geometry. Temperature estimation errors based on numerical
simulations with focus on near infrared are compared in this paper in a variety of scenarios assuming target
temperatures between 1000 to 1600 Kelvin. In one scenario is the measured radiation corrected to minimize the
error due to reflection.
We report about applications of nonlinear optical processes for laser beam and optics characterization. The basic mechanism of the measurements consists in scanning a thin film of a liquid crystal in the focal region of a laser beam and processing the self-phase modulation signal. This technique allows precise and quick determination of the focal waist position and radius, which, in conjunction with the parameters of the focusing system allows determination of the laser beam divergence. We have demonstrated the capabilities of the technique for measuring submicron waist sizes and characterizing astigmatic optical systems. The technique is applicable to short laser pulses. The measurements were performed using the device implementation of the technique, the Crystal Scan Optical Multimeter.