Fabrication of pyroelectric laser-energy meters and their characterization using Nd:YAG laser of variable pulse-width

This paper reports the fabrication and performance-testing of two types of laser-energy meter based on the pyroelectric effect in a crystal (triglycine sulphate, TGS), namely metal-coated TGS and black-coated TGS. A comparison is made between these two types of sensors in terms of response time and sensitivity. Variation of the output response of the energy meter with laser pulse-width is analysed and verified. When the pulse-width of the laser is greater than the response time of the energy meter, the output signal is found to depend on the input capacitance of the circuit. Experiments done with different laser pulse-widths confirm the mathematical formulation given in this paper. The basic parameters for designing a laser-energy meter are described, and the results are validated against experimental data obtained by measurements with an Nd:YAG laser of variable pulse-width.