Laser pulse detector based on Sn-doped indium oxide films

Sn-doped indium oxide (ITO) films have been investigated for fast rise time laser pulse detection for the first time. The detector was tested for diff erent wavelengths in the UV (280 nm, resulting in interband transitions of electrons) and NIR (1.06 mu m, resulting in free carrier absorption) region . Characteristics of laser induced voltages for the ITO films with differen t compositions have been studied for both excitation wavelengths. The volta ge pulse generated by NIR-excitation was delayed in time at least by 100 ns as compared with that generated by UV-excitation. Responsivity of the film s is larger for the UV-excitation than for the NIR-excitation.