NPTEL SWAYAM initiative provides such online courses, which can be accessed on below mentioned website.

Optical Sensors

By Prof. Sachin Kumar Srivastava   |   IIT Roorkee

https://onlinecourses.nptel.ac.in/noc22_ph01/preview

Hi Kim, http://www.co-journal.com/EN/10.3969/j.issn.1000-1093.2020.11.023

I hope this article serves you, kind regards

Hi Kim, http://www.co-journal.com/EN/10.3969/j.issn.1000-1093.2020.11.023

I hope this article serves you, kind regards

Hi Kim, http://www.co-journal.com/EN/10.3969/j.issn.1000-1093.2020.11.023. I hope this article serves you, kind regards