Experimental Verification of Signal Perturbation Applied to the Accuracy of Position Detection

Photodiodes and photo transistors are presently being applied to many fields to convert optical signals into electrical signals. One application of these devices is in a position detection system. The accuracy of such a system is limited by nonlinearities due to these devices. Through signal perturbation, a method in which an extra signal of higher frequency is added to the input of the receptor, the nonlinearities can be altered and the accuracy improved. The theory for this technique is well understood; however, very little experimental data have been reported. This method has been experimentally tested and the results have been compared with those predicted by the theory.