Confocal Imaging of Thermal Lensing Induced by Near-IR Laser Radiation in an Artificial Eye

A custom confocal imaging system was built and used to record a probe beam's spatiotemporal response to a thermal lens induced by a near-IR laser radiation source in a water-filled artificial eye. The IR laser radiation input power levels were varied between 150 and 890 mW at wavelengths of 1110, 1130, 1150 and 1318 nm in order to determine the strength of the resulting thermal lens as a function of time, input power, and wavelength. A high-frame-rate camera captured the probe beam's logarithmic excitation and exponential decay caused by the thermal lens (supplemental video data are provided). Data showed that for equivalent input powers and beam geometries, thermal lensing was strongest for the 1150-nm laser radiation wavelength followed by 1130, 1318 and 1110 nm.