his childhood and adolescence, Mitra nurtured his interest in science through reading popular scientific articles by leading Bengali scientists, including some by Jagadish Chandra Bose. After passing his examinations from the Bhagalpore Zilla school, Mitra was admitted to the FA (intermediate-level) program at the T.N.J. College; his father Joykrishna died shortly after. After passing his FA examinations in 1908, Mitra was admitted as a student in Presidency College of the University of Calcutta where he earned a B.Sc. He continued to develop a passion for physics and scientific research, and was accepted by Jagadish Bose as a research scholar upon completing his master's degree in 1912 with the highest honours. He worked under Professor Bose for a few months before being forced to end his studies due to his family's financial difficulties. University studies and research in France To support his family, after leaving the University of Calcutta, Mitra secured an appointment as a lecturer at his former college, T. N. J. College. Following a brief period there, he was appointed a lecturer at Bankura Christian College. Frustrated by the lack of research opportunities at both institutions, Mitra channelled his energy into developing innovative experiments to demonstrate to his students and writing popular scientific articles in Bengali. In 1916, he was invited by Ashutosh Mukherjee to return to Calcutta University as a post-graduate physics scholar in the new University Science College. There he conducted research into the diffraction and interference of light under C. V. Raman, enhancing Raman's previous research on the diffraction of monochromatic light in an oblique single slit and also devising a better method for determining heliometer diffraction patterns. For this work, which Raman greatly appreciated, Mitra gained a D.Sc. degree in 1919. He also published three papers in the Philosophical Magazine, including one on "Asymmetry of the Illumination Curves in Oblique Diffraction", and another on Arnold Sommerfeld's approaches to diffraction. After receiving his doctorate, Mitra left for France in 1920 to continue his studies at the University of Paris. There he earned a second doctorate under Charles Fabry in 1923, for a thesis on the determination of wavelength standards in the 2,000–2,300 Å region of copper. He subsequently worked briefly under Marie Curie at the Curie Institute. Made aware of continual developments in the new science of radio communications, Mitra went to the University of Nancy and joined the laboratory of Camille Gutton. Under Gutton, Mitra