A new acousto-optic tunable filter (AOTF) that has a wide spectral tuning range, high resolution, no sidelobe, and requires low rf power was designed and developed. This filter fabricated from TeO2 is based on a novel collinear configuration in which the acoustic wave is collinear with the optical beam. However, different from the traditional collinear AOTF, the diffracted beam emerging from this filter is spatially separated from the transmitted beam. As a consequence, this collinear beam AOTF (CB-AOTF) has the combined advantages of the collinear AOTF and the noncollinear AOTF. Specifically, it requires only 350 mW rf power, which is about 14 times lower than the driving power required by a noncollinear AOTF with the same aperture. Even at this nominal rf power, the filter can diffract light for a spectral range of at least 600 nm with a relatively constant diffraction efficiency of about 70% for the entire tuning region. This diffraction efficiency is about 43% higher than the corresponding noncollinear AOTF. More importantly, the CB-AOTF has no sidelobe. Results of the comparison study of the CB-AOTF, noncollinear AOTF, and integrated AOTF clearly demonstrate that this CB- AOTF has the combined advantages of the other two devices and hence is particularly suited for applications in spectroscopy as well as telecommunication.