Black Phosphorous and Cytop Nanofilm-Based Long-Range SPR Sensor with Enhanced Quality Factor

<jats:p>This numerical work proposes two novel designs of long-range surface plasmon resonance sensors (LRSPR) using two different coupling prisms. The performance analysis of the proposed sensor has been investigated using the performance parameters like quality factor (<jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1"> <mi>Q</mi> </math> </jats:inline-formula>), detection accuracy (DA), sensitivity (<jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2"> <mi>S</mi> </math> </jats:inline-formula>), and full-width half maximum (FWHM). The transfer matrix method (TMM) has been employed to compute reflectance. The role of the basic recognition element (BRE) has been played by the popular two-dimensional (2D) material, black phosphorus (BP), due to its many optoelectrical features. The maximum obtained values for <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M3"> <mi>Q</mi> </math> </jats:inline-formula>, DA, and <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4"> <mi>S</mi> </math> </jats:inline-formula> are 3333.25 <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M5"> <mfenced open="(" close=")"> <mrow> <mn>1</mn> <mo>/</mo> <mtext>RIU</mtext> </mrow> </mfenced> </math> </jats:inline-formula>, 250 <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M6"> <mfenced open="(" close=")"> <mrow> <msup> <mrow> <mtext>degree</mtext> </mrow> <mrow> <mo>−</mo> <mn>1</mn> </mrow> </msup> </mrow> </mfenced> </math> </jats:inline-formula>, and 13.33333 degree/RIU for 2S2G coupled sensor design and 3055.5<jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M7"> <mtext> </mtext> <mfenced open="(" close=")"> <mrow> <mn>1</mn> <mo>/</mo> <mtext>RIU</mtext> </mrow> </mfenced> </math> </jats:inline-formula>, 83.33 <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M8"> <mfenced open="(" close=")"> <mrow> <msup> <mrow> <mtext>degree</mtext> </mrow> <mrow> <mo>−</mo> <mn>1</mn> </mrow> </msup> </mrow> </mfenced> </math> </jats:inline-formula>, and 36.66667 degree/RIU for BK7 coupled sensor design. The operating wavelength of 633 nm, followed by the principle of attenuated total reflection (ATR), has been employed to carry out the theoretical investigation.</jats:p>