Rajeev Ranjan was born in India. He received the master’s degree in engineering physics from the National Institute of Technology Warangal, Warangal, India, in 2011. He joined Siemens Corporate Research and Technologies, Bangalore, India, as an Intern. Then, he joined the ISRO, India (Indian Space Research Organization, Laboratory of Electro Optics System), where he was engaged in research on the applied optics area. He obtained his Ph.D. degree from the Department of Engineering, Parthenope University of Naples, Naples, Italy, in 2017, with a thesis about optical sensors based on the optical fiber and fabrication of novel fiber gratings. As a PhD research candidate, his main research was focused on electric arc discharge technique used for the fabrication of Long Period Gratings Sensors in different kinds of optical fibers. During his project, he was responsible for fabrication of Long Period Gratings Sensors in different kinds of optical fibers starting from standard Corning SMF, specialty fibers and to the new generation solid core photonic crystal fiber. He is currently with National Research Council (CNR), Institute for Microelectronics and Microsystems (IMM-Napoli unit), Napoli, where he is involved in the research activity based on non-liner optical imaging. The main project leads to design and development of the microscope based on the femtosecond stimulated Raman scattering (fs-SRS). The device is the combination of SRS spectroscopy and SRS microscope, which is exclusively design and developed for the imaging of the lipids droplets and other biological species and chemical isotopes. The aim of this project to carry out the microscopic imaging of the live cells and C-D bonds. His research resulted with numerous peer-reviewed scientific publications in journals and proceeding of conferences.