Hi! I'm Raktim Haldar. Welcome to my Homepage! I am a curious researcher, but above all, I am a human with numerous flaws, trying to improve myself daily. I'm passionate about science, eager to explore the colors of life, and an amateur painter, photographer, and I enjoy communicating science in an interesting way. You are free to contact me with any questions, send good wishes, or death threats. Surely, I would revert you back if I am alive!

 I was born in the city of Joy, Kolkata, India (1989). My father is a retired government employee, and my mother is a housewife. I'm an assistant professor at the Electronics and Communication Engineering Department, Indian Institute of Technology Bhubaneswar (IITBBS). I'm also a chair of the Optical Metrology Group at Optica. Just before that, I was a postdoctoral researcher at the Institute of Photonics (IOP), Hannover Center for Optical Technologies (HOT), and Cluster of Excellence PhoenixD, Leibniz University Hannover (TU Hannover), Germany, working with supervisor Prof. Dr. Michael Kues since 2020. I was an Alexander von Humboldt (AvH) fellow at the same institute for two years starting in 2021.  In Sept. 2022, I also served as a guest scientist at the Paris Centre for Quantum Computing, Pierre and Marie Curie Institute, Sorbonne University, France. The campus is just beside the mighty Panthéon, the tomb of the great physicist Marie Curie! Does that give you goosebumps? Yes, for me, it does.  

But what do we do in those Institutes, in those labs day and night? 

We are building quantum computers and quantum internet using light. Let me explain - 

Quantum mechanics govern the behavior of tiny particles, e.g., electrons, protons, photons (light quanta). The 'quantum world' is invisible yet invincible. It is bizarre. It is magical, romantic, a 'la la land'! Quantum technologies hold extraordinary promises to humankind by taming utter strangeness and harnessing the unfathomable power offered by the hidden nonclassical world revolving around us. To utilize that indomitable power of quantum mechanics, we domesticate superfast tiny photons in our lab. We generate pairs of entangled photons on a daily basis in very small chips. These entangled photons can simultaneously stay in many places! These photons are 'spooky,' behave strangely, as Einstein named them once. We use them as the data carriers similar to electronic bits. In short, we call them 'qubits' (quantum bits). These entangled photons are helpful in building quantum computers and quantum internet, which can revolutionize the world as we know it today. Scientists call this emerging technology - 'Integrated Quantum Photonic Technologies.' Why integrated, and why photonic? Because we realize this technology on chips, which are driven by light (photons). Why do we use light? Because light has less noise, and it is easier to carry information through light directly to your house using the optical-fiber internet cables. 

Additionally, I am involved in designing 'photonic computers' that use light (stream of photons) instead of current (flow of electrons). This technology (while still classical) is expected to replace today's 'electronic computers' very soon. Photonic computers will be much faster (defying Moore's law), more energy efficient, and will allow us to download movies in a fraction of a second! Doing research on quantum technologies combined with photonics gives me goosebumps, acting as a driving force and a good reason for why I am living. 

Therefore, my present research goal is to bridge the gap between integrated photonics and fundamental physics at the nanoscale. My future goal is to develop indigenous experimental quantum photonic technology facilities and to play a role in the quantum revolution 2.0, no matter how insignificant it might be!  

 I have done my Ph.D. under the supervision of Prof. Shailendra K. Varshney from the Electronics and Electrical Communication (E & ECE) department, Indian Institute of Technology Kharagpur (IIT Kharagpur). I have received an M. Tech. degree from the same department with a specialization in RF and microwave Engineering in 2013. My research interests include silicon photonics and plasmonics, optical waveguides, electromagnetic theory, fiber optic communication systems, photonic crystal fibers, integrated, nonlinear, and quantum optics, quantum computation and optimization techniques using different evolutionary algorithms, etc. During my M. Tech and Ph.D. tenure, I have served as a teaching assistant for microwave engineering, satellite communication, optical communication, nonlinear optics, and introductory electronics courses. I have authored and co-authored several peer-reviewed journals and international conferences. I am also a regular reviewer of many prestigious journals, such as Nature Photonics, APS journals, and Phys. Rev. Appl., Phys. Rev. Lett., Phys. Rev. Research, Phys. Rev. X., Phys. Rev. A., OSA journals, Applied Optics, Optics Express, JOSA B, Photonic Research, IEEE Photonics Journal, SPIE journal Optical Engineering, MDPI journal Micromachines, etc. Being a student member of the Optical Society of America (OSA) since 2015, I was actively involved in various activities of the OSA-student chapter, IIT Kharagpur, and was on the organizing committee of Photonics 2014 and IONS 2014. I served as the IITKGP OSA Student Chapter as a President for 2018-2019. I am also a lifetime member of SPIE and IEEE.

 Ok, if you are still surviving and have finished reading up to this point, you might think I am a geek or a nerdy without a life outside academics. Yeah, that is partially true, but I'm not quite as nerdy as per the Oxford Dictionary definition. I am quite a gregarious person with the companies I prefer!

I grew up in a big city amidst buildings, but at the same time, it is one of the most prominent cultural cities in the world, having many Nobel Laureates in literature, science, and economics. I played cricket on the street of my lane, was a 'kite runner,' and played chess with the same vigor. I spent time sitting inside Belur Math, beside the holy Ganges river, which flows through the heart of my city. I returned home past midnight surreptitiously with my friends after Durga Puja pandal hopping from the afternoon. 

Everyone born in this city indulges in at least one extra-curricular activity. I am not an exception. My hobby is painting. I perceive the world or the mood of a person by colors. I can map the expression, whether a person is friendly or just judging me, and translate it into the variegated shades of colors. I visualize instances and convert them into cartoons to finally decide who would treat me positively, who is kind to me, and who is blind or ignorant of society. I love to read story books, write popular science articles, and sometimes do photography. Some of my paintings and photographs I have taken can be found on this website. I'm currently writing many popular science articles (which can be found on my website) and a few articles on the history of art or the evolution of art in Bengal. I spent significant time in Paris, the city of light, to research 'quantum' light and simultaneously explore France's art and culture. I roamed around the Montmartre and visited many museums (Louvre, Orsay, Rodin, Picasso) to establish a connection between arts and science. 

I always try to wonder about several things, transcending conventional and stereotype boundaries. My mind tends to hover not just on scientific topics like why time is unidirectional or whether we can ever know how physics works inside a black hole, but I am also astonished by the coarse brush strokes Claude Monet used to illustrate water lilies in his 'Nymphéas' series. I am amazed to find a relationship between Picasso's cubism and topological photonics, whereas Rabindra Nath Tagore's poems touch my heart deeply. I search for perennial sources of inspiration so that I can do impactful research, create fluent literature, or produce colorful art. I pray that my strive to improve the quality of life for any human in any corner of the world will continue till the last day of my life. If you are a reader of my website, then I do need your help there! Let's navigate through the ebbs and flows of our lives together and help each other make this world better, fighting against all odds. 

A list of a few story books that will inspire you throughout your life can also be found in the 'Resources' Tab, along with many other exciting ones! The 'Resources' tab is dedicated to you...so keep an eye on the tab frequently!