Abstract
In an optical fiber based SPR sensor, a segment of metal clad silica fiber is used as the sensing element and resonant coupling occurs to the surface plasmon mode excited at the interface of the metal and ambient which surrounds the sensing element. When polychromatic light is transmitted through the sensing element, the spectrum of light detected at the other end shows minima at a resonance wavelength. In wavelength interrogation, the shift in the resonance wavelength is a measure of change in the refractive index of the ambient. Alternatively, intensity interrogation can be used in which the change in transmitted power at a given wavelength is a measure of change in refractive index of the ambient. The sensitivity and detection accuracy of the sensor depend on the numerical aperture (NA) of the multimode optical fiber used to fabricate the sensor. In the present work, we have carried out a study of the dependence of the sensitivity and detection accuracy on numerical aperture to obtain the optimal value for a multimode optical fiber which is used to fabricate the sensing element under both wavelength and intensity interrogation. For a gold clad sensing element with l/a = 33.33 for the refractive index of the ambient in the range 1.33 to 1.38, the optimized numerical aperture is obtained as \(NA\)= 0.2 for spectral interrogation mode. At this optimal value, the sensitivity is estimated to be 4040 nm/RIU and detection accuracy lies between 20 and 48 μm−1. In single wavelength intensity interrogation, at the He–Ne laser wavelength (633 nm), the optimized numerical aperture is obtained as \(NA\)= 0.42. Experimental results on a sensing element fabricated with gold coating on the core of a plastic clad silica fiber are also reported.
Similar content being viewed by others
References
Homola J, Sinclair S, Gauglitz GY (2006) Surface plasmon resonance sensors: review. Sensor and Actuators B 115:344–348
Baliyan A, Bhatia P, Gupta BD, Sharma EK, Kumari A, Gupta R (2013) Surface plasmon resonance based fiber optic sensor for the detection of triacylglycerides using gel entrapment technique. Sensors and Actuators B 188:917–922
Bhatia P, Gupta BD (2013) Surface plasmon resonance based fiber optic ammonia sensor utilizing bromocresol purple. Plasmonics 8:779–784
Singh S, Gupta BD (2013) Fabrication and characterization of a surface plasmon resonance based fiber optic sensor using gel entrapment technique for detection of low glucose concentration. Sensors and Actuators B 177:589–595
Prado AR, Díaz CAR, Nunes LGL, Oliveira JP, Guimarães MCC, Junior AL, Ribeiro MRN, Pontes MJ (2021) Surface plasmon resonance based optical fiber sensors for H2S in situ detection. Plasmonics 16:787–797
Kretschmann E, Raether H (1968) Radiative decay of non radiative surface plasmons excited by light, Z. Naturforsh 23:2135–2136
Homola J (1997) On the sensitivity of surface plasmon resonance sensors with spectral interrogation. Sensor and Actuator B 41:207–211
Gwon HK, Lee SH (2010) Spectral and angular responses of surface plasmon resonance based on the Kretschmann prism configuration. Mater Trans 51:1150–1155
Paliwal A, Gaur R, Sharma A, Tomar M, Gupta V (2016) Sensitive optical biosensor based on surface plasmon resonance using ZnO/Au bilayered structure. Optik 127:7642–7647
Paliwal A, Sharma A, Tomar M and Gupta V (2016) Surface plasmon resonance study on the optical sensing properties of tin oxide (SnO 2 ) films to NH3 gas. J Appl Phys 119:164502
Paliwal A, Tomar M, Gupta V (2019) Refractive index sensor using long-range surface plasmon resonance with prism coupler. Plasmonics 14:375–381
Gupta BD, Srivastava SK, Verma R (2015) Fiber optics sensors based on plasmonics. World Scientific
Odaci C, Aydemir U (2021) The surface plasmon resonance-based fiber optic sensors: a theoretical comparative study with 2D TMDC materials. Result in Optics 3:100063
Gandhi MSA, Chu S, Senthilnathan K, Babu PR, Nakkeeran K, Li Q (2019) Recent advances in plasmonic sensor-based fiber optic probes for biological applications. Appl Sci 9:949
Prabowo BA, Purwidyantri A, Liu KC (2018) Surface plasmon resonance optical sensor: a review on light source technology. Biosensors 8:80
Haddouche I, Cherbi L, Ferhat ML (2017) Analytical modelization of a fiber optic-based surface plasmon resonance sensor. Opt Commun 402:618–623
Mao P, Luo Y, Chen C, Peng S, Feng X, Tang J, Fang J, Zhang J, Lu H, Yu J, Chen Z (2015) Design and optimization of surface plasmon resonance sensor based on multimode fiber. Opt Quant Electron 47:1495–1502
Sharma AK, Pandey AK, Kaur B (2018) A review of advancements (2007–2017) in plasmonics-based optical fiber sensors. Opt Fiber Technol 43:20–34
Adams MJ (1981) An introduction to optical waveguides. John Wiley & Sons
Sital S, Sharma EK (2014) Excitation of leaky surface plasmon modes in sensors, International Conference on Optics and Optoelectronics, ICOL 2014, 5–8 March 2014, IRDE Dehradun, India
Gupta BD, Sharma A, Singh CD (1993) Evanescent wave absorption sensors based on uniform and tapered fibers. Int J Optoelectron 8:409
Gupta BD, Singh CD, Sharma A (1994) Fiber-optic evanescent field absorption sensor: effect of launching condition and the geometry of the sensing region. Opt Eng 33:1864–1868
Funding
The authors would like to thank the Council of Scientific and Industrial Research (CSIR), Ministry of Science and Technology, Government of India for the financial support.
Author information
Authors and Affiliations
Contributions
All authors contributed to the study conception and design. Material preparation, data collection, and analysis were performed by Shivani Sital and Anjli Baliyan. The first draft of the manuscript was written by Shivani Sital and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
Corresponding author
Ethics declarations
Ethics Approval
This is an observational study. Hence, no ethical approval is required.
Consent to Participate
Not applicable.
Consent for Publication
Not applicable.
Competing Interests
The authors declare no competing interests.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Sital, S., Baliyan, A., Sharma, E.K. et al. Optimization of Multimode Fibers for Surface Plasmon Resonance Based Sensors Under Spectral and Single Wavelength Intensity Interrogation. Plasmonics 17, 665–673 (2022). https://doi.org/10.1007/s11468-021-01556-w
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11468-021-01556-w