Ronald L. Walsworth

The GMT-consortium large earth finder (G-CLEF): an optical echelle spectrograph for the Giant Magellan Telescope (GMT)

The GMT-Consortium Large Earth Finder (G-CLEF) is an instrument that is being designed to exceed the state-of-the-art radial velocity (RV) precision achievable with the current generation of stellar velocimeters. It is simultaneously being designed to enable a wide range of scientific programs, prominently by operating to blue wavelengths (< 3500Å). G-CLEF will be the first light facility instrument on the Giant Magellan Telescope (GMT) when the GMT is commissioned in 2023. G-CLEF is a fiber-fed, vacuum-enclosed spectrograph with an asymmetric white pupil echelle design. We discuss several innovative structural, optical and control system features that differentiate G-CLEF from previous precision RV instruments.

Visible Spectrum Frequency Comb for Astronomical Spectrograph Calibration

We have developed a visible wavelength frequency comb at 420nm with a 21GHz mode spacing to calibrate astronomical spectrographs used in searches for planets similar to the Earth near stars similar to the Sun.

Toward Manipulating Quantum Information with Atomic Ensembles

We review several ideas for manipulation of quantum information using atomic ensembles and photons and describe some preliminary experiments toward their implementation. In particular, we review a technique that allows for robust transfer of quantum states between light fields and metastable states of matter. Next we discuss the use of Raman scattering to produce robust entanglement of atomic ensembles via realistic (i.e., absorbing) channels. Finally, we present preliminary experimental results related to the implementation of entanglement via Raman scattering. Specifically, we present experimental studies of the intensity fluctuations in resonantly enhanced Raman scattering from a warm 85Rb vapor cell under conditions of EIT. A crossover between the Bose-Einstein and Poisson statistics of Raman light is observed and it is shown that the noise properties of Raman fields can be mirrored in transmitted pump beams.