Development of free electron lasers in the country, which began with the first experimental observation of undulator radiation at IPR, Gandhinagar, has now reached a level of maturity with the Infra-red Free Electron Laser at RRCAT operated regularly as a user facility, and the Delhi Light Source at IUAC in an advanced stage of commissioning. The wavelength tunability of the Infra-red Free Electron Laser (IR-FEL) radiation at RRCAT has been confirmed in the range 12.5 - 50 micrometer, and more than 7 MW peak out-coupled power and ~25 mW Continuous Wave (CW) average out-coupled power at 21.8 micrometer wavelength and 2 Hz macropulse repetition rate (PRR) has been achieved. The CW power reaching the experimental stations has now been measured as 14 mW (at 19.1 micrometer wavelength), which translates to more than 50 micro-Joules over 10 ps width micro pulses for 2 Hz PRR. The layout of the experimental facilities, consisting of six user ports, as planned to be developed over the next 3- 4 years for the utilization of the IR-FEL light, has been finalized, and three ports are already in operation for user experiments.

            With the IR-FEL now serving as a user facility for users from outside as well as from within RRCAT since December 2024, the first "User Interaction meeting on Science with IR/THz Free Electron Lasers" is being organized at RRCAT on January 29 - 30, 2026 under the sponsorship of India Society for Particle Accelerators (ISPA). This interaction meeting is focused on the ongoing as well as potential utilization of the user stations presently commissioned at the IR-FEL based user facility in RRCAT. Participation in the user interaction meeting is proposed to be primarily by the existing and potential users of the facility, including researchers who have expressed keen interest in performing experiments using the IR-FEL light in recent past. The main motivation behind the interaction meeting is to increase the user base of the IR-FEL. The attached file contains the poster for the interaction meeting. Participation in the user interaction meeting is through invitation only, and there is no registration fee for the participants.