One-dimensional photonic crystal to detect lactose concentration present in milk: A theoretical approach

A one-dimensional photonic crystal structure is theoretically investigated as a potential optical sensor for determining the amount of lactose present in milk. The proposed structure is composed of two conventional one-dimensional photonic crystal structures with a defect layer sandwiched between them. The transmission characteristics of the structure are examined using the transfer matrix approach. The theoretical model is designed and analyzed using MATLAB simulation tool, and the transmission spectrum is obtained. According to the obtained results, the proposed structure has a high sensitivity of 673 nm/RIU, quality factor of 1.12 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> and figure of merit of 48×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>RIU<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>. This paper also examines the impact of incidence angle and defect layer thickness on the performance parameters of the suggested sensor.