We present diffraction-limited \ks band and \lprime adaptive optics images ofthe edge-on debris disk around the nearby F2 star HD 15115, obtained with asingle 8.4 m primary mirror at the Large Binocular Telescope. At \ks band thedisk is detected at signal-to-noise per resolution element (SNRE) \about 3-8from \about 1-2\fasec 5 (45-113 AU) on the western side, and from \about1.2-2\fasec 1 (63-90 AU) on the east. At \lprime the disk is detected at SNRE\about 2.5 from \about 1-1\fasec 45 (45-90 AU) on both sides, implying moresymmetric disk structure at 3.8 \microns . At both wavelengths the disk has abow-like shape and is offset from the star to the north by a few AU. A surfacebrightness asymmetry exists between the two sides of the disk at \ks band, butnot at \lprime . The surface brightness at \ks band declines inside 1\asec(\about 45 AU), which may be indicative of a gap in the disk near 1\asec. The\ks - \lprime disk color, after removal of the stellar color, is mostly greyfor both sides of the disk. This suggests that scattered light is coming fromlarge dust grains, with 3-10 \microns -sized grains on the east side and 1-10\microns dust grains on the west. This may suggest that the west side iscomposed of smaller dust grains than the east side, which would support theinterpretation that the disk is being dynamically affected by interactions withthe local interstellar medium.
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