High Resolution Absorption Spectroscopy using Externally Dispersed Interferometry
We describe the use of Externally Dispersed Interferometry (EDI) for high-resolution absorption spectroscopy. By adding a small fixed-delay interferometer to a dispersive spectrograph, a precise fiducial grid in wavelength is created over the entire spectrograph bandwidth. The fiducial grid interacts with narrow spectral features in the input spectrum to create a moire pattern. EDI uses the moire pattern to obtain new information about the spectra that is otherwise unavailable, thereby improving spectrograph performance. We describe the theory and practice of EDI instruments and demonstrate improvements in the spectral resolution of conventional spectrographs by a factor of 2 to 6. The improvement of spectral resolution offered by EDI can benefit space instruments by reducing spectrograph size or increasing instantaneous bandwidth.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 877853
- Report Number(s):
- UCRL-PROC-214587; TRN: US200608%%590
- Resource Relation:
- Journal Volume: 5898; Conference: Presented at: SPIE Optics & Photonics, San Diego, CA, United States, Jul 31 - Aug 04, 2005
- Country of Publication:
- United States
- Language:
- English
Similar Records
Externally Dispersed Interferometry for Precision Radial Velocimetry
High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: Part 2, photon noise theory