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Increasing the length of a micro-bridge by folding into a meander is a conventional way of increasing photo-response for bolometers. Experiment results indicate that the photo-response does not increase linearly with the number of meander folds of bolometers as expected but depends on the pulse frequency of the incident light. The photo-response increases with the number of folds only when the number is small and decreases when it is large. An optimum response to light can be found to be at a specific number of folds. This phenomenon is attributed to the differences of the heat dissipation at the center and at the outermost micro-strip of meanders. At the center of meanders, the heat dissipation from a micro-strip can only flow in the perpendicular direction into the substrate because the sideward dissipation capability is canceling with that of the other micro-strips next to it. For the lateral part of a meander, the heat can dissipate into both perpendicular and sideward away from the center of meanders. The combination of these two behaviors limits the number of folds. Only a certain number of folds provides the optimum photo-response in different pulse frequencies.
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