Emerging Technologies and Designs for Far- UV Integral-Field Spectroscopy on HWO

[Presented at HWO25 "Towards the Habitable Worlds Observatory: Visionary Science and Transformational Technology"] 

Astronomy in the Far-UV is primarily the study of nearby objects, from stars and nebulae in the Milky Way to galaxies at redshift z < 1. At these distances, especially with the large aperture and exquisite angular resolution of the Habitable Worlds Observatory (HWO), most of the non-stellar sources are brilliant and beautiful objects, yet the tools that have existed to-date are not suited to extended source spectroscopy. A wide-field multi-object spectrograph (MOS) enables far more efficient sampling of clusters and cross-sections of gaseous clouds, but is only marginally more efficient at mapping the gas distribution, structure, and kinematics across two-dimensional fields than a traditional long-slit. With the development of large format, photon-counting detectors, advanced broadband mirror coatings, micro-mirror devices, and efficient aberration-correcting gratings, this technology- limited paradigm has changed. This talk presents several new instruments and designs for integral-field spectroscopy, some that have already been deployed and others that are in development. These designs are readily scalable, and we conclude with a draft architecture and parameter trade space for an efficient, powerful, yet low- cost instrument for UV integral-field spectroscopy on HWO.