New instrument concepts for observational cosmology

A key goal of observational cosmology today is to understand what initiated the re-ionization epoch and how this spectacular phase unfolded over a period of a few hundred million years. Simulations show that this may ultimately require us to push observations to redshifts as high as z ∼ 25. Here, I explore present and planned activities that will allow us to go beyond our current redshift limit (z ∼ 6.5). We stand at the dawn of a new era where diffraction-limited observing will be possible on 8 m class telescopes at near infrared wavelengths. I describe some of the instrument concepts that lead naturally from the science cases, in particular an AO-assisted, OH-suppressed IFU spectrograph. The benchmark for these new concepts has been set by the James Webb Space Telescope (JWST). Can we expect the next instruments to live up to this goal? If we do succeed, a great deal of entirely new science will be possible long before the expected launch of JWST.