Response of edge- and face-electroded pyroelectric detectors to infrared laser signals

Expressions are given for the peak voltage responses to infrared laser signals in pyroelectric detectors with edge electrodes (EE) and face electrodes (FE). When the response is independent of the capacitance C_s of the samples, the FE detector has a much higher responsivity. When the response depends on C_s and the capacitance C_i of the preamplifier input is negligible for both samples, the EE design can give only a slightly higher response (the high gain expected in the literature comes from considering the EE sample as a parallel-plate condenser). However, when C_sEE << C_i << C_sFE, the EE detector response is higher by a factor of εl/C_i, where ε is the permittivity and l is the length of the edge electrodes.