Single-mode Fiber Length for Wavefront Filtering

Stellar nulling interferometry offers the possibility of direct imaging of extrasolar planets necessary for the detection of extra-terrestrial life. Achieving optimum performance from the interferometers requires that the wavefronts of light reaching the interferometer are free of distortions. This is achieved by using single-mode fibers, which are excellent wavefront filters. In this paper, we present an improved theoretical model to estimate the minimum fiber length required to achieve a certain degree of filtering and show that the effects of both the fiber characteristics and launching conditions of the input optical field should be considered to determine the minimum length.