Optical Sensors

By Prof. Sachin Kumar Srivastava   |   IIT Roorkee
Learners enrolled: 434
This course provides detailed insight of the field of optical biosensors and their basic working principles. Staring with the introduction of basic components, characteristics, performance parameters and fabrication techniques (lectures 1&2), this course brings the learner to the mesmerizing field of sensors based on basic principles of optics. The basic optical phenomena/characteristics and their sensing applications have been discussed in detail (lectures 3-8). In the last two lectures, the optical properties of tissues and optics in the biomaterials has been discussed with providing some further insights into optical biosensing applications. The course ends with notes on terahertz sensing applications and future directions of research.

INTENDED AUDIENCE : Physics, Nanotechnology, Biosciences, Electrical Engineering, Electrooptic Engineering, Photonics
PREREQUISITES : Basic knowledge of Optics (Geometrical optics, Interference, Diffraction, polarization, etc.)
Course Status : Upcoming
Course Type : Elective
Duration : 4 weeks
Start Date : 24 Jan 2022
End Date : 18 Feb 2022
Exam Date : 27 Mar 2022 IST
Category :
  • Physics
  • Photonics
Credit Points : 1
Level : Undergraduate/Postgraduate

Course layout

Week 1 : Lecture 1: Introduction to sensors and biosensors:Characteristics and components of optical biosensors,various transduction mechanisms, Optical probing parameters
Lecture 2: Performance parameters, Fabrication and functionalization methods of optical biosensors
Lecture 3: Basic optics for optical biosensing-I:Electromagnetic waves in free space: –Maxwell’s equations, EM Wave equations, Power density, Polarization, Scattering
Week 2 : Lecture 4: Basic optics for optical biosensing-II: Electromagnetic waves in matter Dielectrics, Reflection and transmission at interface: Fresnel equations, Polarization by reflection – Brewster angle sensor
Lecture 5: Basic optics for optical biosensing-III: Electromagnetic waves in matter Total internal reflection- TIR sensors, Evanescent wave sensing, factors affecting performance, importance of penetration depth, waveguide sensors using TIR
Lecture 6: Basic optics for optical biosensing-IV: Electromagnetic waves in matter Absorption and dispersion, conductors: Drude model for the metal dielectric function and introduction to plasmons
Week 3 : Lecture 7: Plasmonic sensors: Propagating versus localized plasmons, Optimized sensor configurations, Electromagnetic field enhancements, plasmon enhanced sensors
Lecture 8: Basic optics for optical biosensing-V: Interference and diffraction Interference and interferometry, Airy function for single layer, Mach Zehnder Interferometer for sensing, Fabry Perot Interferometer for sensing.
Week 4 : Lecture 9: Review of biomaterial optics:Biomaterial Structures EM Waves Absorption in Tissue, Chirality, polarization rotation and dichroism,
Lecture 10: Review of sensing applications: Scattering–Elastic (Rayleigh), –Inelastic (Raman); Fluorescence, Some real life optical biosensors, Sensing at terahertz.

Books and references

1. “Fiber Optic Sensors Based on Plasmonics” B.D. Gupta, S.K. Srivastava and R. Verma, World Scientific Pub. Co. (2015).
2. “Optical Sensors: Industrial, Environmental and Diagnostic Applications” Edited by R. Narayanswamy, Springer (2004)
3. “Optical Sensors: Basics and Applications”Jörg Haus, Wiley-VCH, GmBH (2010).

Instructor bio

Prof. Sachin Kumar Srivastava

IIT Roorkee
I am an Assistant Professor in the Physics department of IIT Roorkee. I have more than 10 years of research experience on working of various dimensions of optical biosensors, starting from evanescent waves, SPR, SERS, EOT, LSPR, SEF, ESP-LSP coupling, GMR and other optical phenomena. I am teaching applied Physics course at IIT Roorkee and have taught Basic optics course at AcSIR. Apart from aforementioned details, I worked as In-charge of technical operations of Photonicsys company in Asia. I am a member of Optical Society of America (OSA) Optical Biosensors and OSA- Nanophotonics executive committees. I also am an Editor of the Journal of Sensors.

Course certificate

The course is free to enroll and learn from. But if you want a certificate, you have to register and write the proctored exam conducted by us in person at any of the designated exam centres.
The exam is optional for a fee of Rs 1000/- (Rupees one thousand only).
Date and Time of Exams: 27 March 2022 Morning session 9am to 12 noon; Afternoon Session 2pm to 5pm.
Registration url: Announcements will be made when the registration form is open for registrations.
The online registration form has to be filled and the certification exam fee needs to be paid. More details will be made available when the exam registration form is published. If there are any changes, it will be mentioned then.
Please check the form for more details on the cities where the exams will be held, the conditions you agree to when you fill the form etc.


Average assignment score = 25% of average of best 3 assignments out of the total 4 assignments given in the course.
Exam score = 75% of the proctored certification exam score out of 100

Final score = Average assignment score + Exam score

YOU WILL BE ELIGIBLE FOR A CERTIFICATE ONLY IF AVERAGE ASSIGNMENT SCORE >=10/25 AND EXAM SCORE >= 30/75. If one of the 2 criteria is not met, you will not get the certificate even if the Final score >= 40/100.

Certificate will have your name, photograph and the score in the final exam with the breakup.It will have the logos of NPTEL and IIT Roorkee.It will be e-verifiable at nptel.ac.in/noc.

Only the e-certificate will be made available. Hard copies will not be dispatched.

Once again, thanks for your interest in our online courses and certification. Happy learning.

- NPTEL team

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