Broadband nulling using a prism phase shifter

Details Broadband nulling using a prism phase shifter Broadband nulling using a prism phase shifter

Oct 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003esasp.539..367b&link_type=abstract

In: Proceedings of the Conference on Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets, 22-25 A

Other

1

Nulling Interferometers, Earth-Like Planets

Scientific paper

Achromatic phase shifters are key components of broadband nulling interferometers. Such interferometers are currently developed for the detection of earth-like planets at nearby stars. The work reported here was carried out in the context of ESA's space-interferometry mission Darwin, scheduled for launch in 2015. To detect a weak object such as an earth-like planet close to a much brighter star requires first of all a very high spatial resolution and in addition a considerable suppression of the starlight. The high spatial resolution is obtained by an array of 6 free-flying telescopes, constituting a synthetic optical aperture. Suppression of the starlight is achieved by creating at the location of the star a small area where destructive interference (nulling) occurs. The remaining, virtually unobstructed planet light, is subjected to low-resolution spectrometry. The wavelength region for these observations is optimized, not only for detecting spectral features indicative of habitable planets, but also for minimizing the brightness gap. Deep nulling at the location of the star, can be obtained with destructive interferometry provided that intensity, phase, polarisation, optical path and wavefront error differences are all extremely small. Since the nulling should be performed over a wide spectral range, a phase difference of π needs to be achieved within a few mrad. This requires an achromatic phase shifter providing a λ/2 optical pathlength difference for each wavelength λ within the spectral range. Achromatic phase shifting can be accomplished in many ways. At TNO TPD most efforts have been directed to a dispersive method developed in cooperation with the Delft University of Technology. This paper describes a breadboard operating in the visible region based on a dispersive phase shifter realized with prisms.

Affiliated with

Also associated with

No associations

Rating

Broadband nulling using a prism phase shifter does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Broadband nulling using a prism phase shifter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Broadband nulling using a prism phase shifter will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-917929