A low-cost readout technique based on a linear sensor array for interferometric biosensor applications

In this paper an interferogram readout technique based on a linear sensor array (LSA) is presented. The operation of the LSA measurement system and signal processing of the LSA signal are described. Results of preliminary measurements using a silicon mirror attached to a moving piezo element (PZT) are presented. For reference, the displacement of the mirror was measured using a commercial reference interferometer, and the measurements using the LSA were compared to those. The results show that both the reference and the LSA measurements followed the piezo displacement linearly. The usage of the LSA is also demonstrated in determining the glucose concentration in water through a concentration range of 0-675 µg/ml increasing in steps of 225 µg/ml. It was found that these steps can be detected using the LSA. Stability problems of a free-space configuration due to temperature variation are also considered and presented.