Advancing Astronomy with Innovative Instruments : From FiberPol, WALOP to the ELT-PCS

Stellar polarimetry is a powerful diagnostic tool to probe dust and magnetic fields in the interstellar medium. In this talk, I will present FiberPol, a newly commissioned spectropolarimetric instrument at the South African Astronomical Observatory (SAAO), where I served as Principal Investigator. It combines two niche techniques--fiber-based spectroscopy and polarimetry. In addition to enabling a wide array of new science, it serves as a technology pathfinder for larger telescopes like the 10m SALT. During commissioning in early 2025, FiberPol's key performance parameters were verified, including its ability to achieve high polarimetric accuracy of 0.1%. Following this success, several science programs are now underway. I will outline the instrument concept, development process, and updates from commissioning. In the second part of the talk, I will present the WALOP instruments developed at IUCAA for the PASIPHAE survey. WALOPs will be the first wide-field (35'x 35'), survey-capable optical polarimeters in astronomy and will be used to create the first large optical polarimetric map of the sky, covering over 2000 square degrees. I will describe the scientific motivation, technical goals, design challenges, and the current status of the instruments. Detection and characterization of earth-like exoplanets is one of the most pressing scientific goals in current day astronomy. In the final part, I will highlight our current work at Oxford on the Planetary Camera and Spectrograph (PCS), the ELT's secondgeneration, dedicated instrument for exoplanet detection and characterization. At Oxford, our group is conducting R&D to identify the optimal spectrograph architecture capable of delivering the high contrast needed to detect potentially habitable Earth-like exoplanets.