  Modal noise in fibers has been shown to limit the signal-to-noise ratio
achievable in fiber-coupled, high-resolution spectrographs if it is not
mitigated via modal scrambling techniques. Modal noise become significantly
more important as the wavelength increases and presents a risk to the new
generation of near-infrared precision radial spectrographs under construction
or being proposed to search for planets around cool M-dwarf stars, which emit
most of their light in the NIR. We present experimental results of tests at
Penn State University characterizing modal noise in the far visible out to 1.5
microns and the degree of modal scrambling we obtained using mechanical
scramblers. These efforts are part of a risk mitigation effort for the
Habitable Zone Planet Finder spectrograph currently under development at Penn
State University.

Instrumentation and Methods for Astrophysics;Earth and Planetary Astrophysics