A sensitive optoelectronic displacement transducer for the neurophysiological laboratory

This paper describes a simple and convenient way of making a sensitive displacement transducer for routine use in the neurophysiological laboratory. It is based upon a commercially available optoelectronic integrated circuit and requires only simple electronic and mechanical fabrication. Its sensitivity is such that it may be used to monitor movements down to approximately 100 nm over a bandwidth of 8 kHz without additional filtering or averaging. Further electronic filtering or computer averaging will extend its sensitivity. It has many potential uses, two examples of which are provided.