Department of Physics, Indian Institute of Technology Bombay, Mumbai, India

ToPP Group

Topological Photonics and Polaritonics Group


  • September 2026: Three of our PhD students, Abhijit, Prem, and Neha, have suessfully defended their first Annual Progress Seminar. Congratulations to all!
  • August 2026: We warmly welcome Mr. Jahidul Islam and Mr. Saurav Prasad as M.Sc. Project Students. Jahidul_Saurav
  • Dr. Deep’s collaborative work on higher-order antichiral hinge states in a three-dimensional gyromagnetic photonic crystal has now been published in Nature Communications. This study demonstrates a novel class of topological photonic systems where robust, tunable, and co-propagating electromagnetic waves are confined along 1D crystal hinges. Deep led the theoretical development of the project and contributed significantly to the experimental design. Deep_NC
    Dr. Deep has also presented his Annual Research Progress Seminar and successfully passed. Heartiest congratulations to him on these double achievements!
  • June 2026: Dr. Dheerendra presented his Annual Research Progress Seminar and successfully passed. Congratulations!

  • May 2026: Ghanshyam presented his work at the IIT Bombay Research Internship Poster Presentation on 22nd May.
  • Harish_Dinner
  • March 2026: It was a pleasure to host Prof. Harish Krishnamoorthy from TIFR Hyderabad, one of the most eminent scientists working in nanophotonics in India, during his visit to Mumbai. The interaction with him was highly enriching for the group. Below is a photo of us with Prof. Harish during dinner.
  • Harish_Dinner

    Clockwise: Abhijit, Dheerendra, Neha, Harish, Subhaskar, Mousam, and Deep.


  • February 2026: Our Ph.D. student, Mousam, has successfully defended his first APS seminar. Congratulations to him on this achievement!

  • January 2026: A group lunch to welcome the new year and cherish all the good moments from the past year.
  • January_Lunch

    Left row: Abhijit, Deep, Subhaskar, Mousam, and Prem. Right row: Sandipan, Dheerendra, Neha, and Ghanshyam.


    We warmly welcome Mr. Abhijit Das as our new Ph.D. student, Mr. Ghanshyam Purohit as an intern under the IIT Bombay Internship Program, and Mr. Sandipan Biswas as an M.Sc. project student. Abhijit_Ghanshyam_Sandipan
  • December 2025: Members of the ToPP Group, along with other members of the Photonics Student Chapter, actively participated in TechConnect 2025.

    To learn more about the activities of the Photonics Student Chapter, please visit the Student Chapter Website.

  • TechConnect25

    From Left: Sandeep, Ikshavaku, Dheerendra, Prem, Muppalla, Subhaskar, Saurav, Parul, Neha, Mousam, and Ekta.


  • November 2025: Prof. Subhaskar delivered an invited talk on “Axion Photonic Crystal” at the OPTIQ Conference in Kochi, Kerala, India [Conference Link].
  • OPTIQ
  • October 2025: Prof. Subhaskar has joined the Editorial Board of Scientific Reports and is a Guest Editor for the Special Issue on Polaritons [Link].
  • Polaritons
  • September 2025: We welcome Dr. Deep Mondal, who has joined us as an Institute Postdoctoral Fellow.
  • Deep_Joining
  • August 2025: We are delighted to host Prof. Daniel Leykam from the Singapore University of Technology and Design (SUTD) during his visit to IIT Bombay. In the photo below: Subhaskar, Dheerendra, and Mousam with Daniel at Marine Drive, Mumbai, India.
  • Daniel_Marine_Drive
  • August 2025: Our group has organized a Workshop on Recent Trends in Optics and Photonics, sponsored by the SCPP project at IIT Bombay [Workshop Link].
  • SCPP_Workshop
  • August 2025: A warm welcome to our PhD students — Mr. Mousam Dey, Ms. Neha Bhoria, and Mr. Prem Kumar Mourya.
  • Mousam_Neha_Prem
  • July 2025: We are pleased to welcome our first group member, Dr. Dheerendra Singh, who joins us as an Institute Postdoctoral Fellow.
  • Dheerendra