Retroreflecting elements adapted for use in one-to-M wavelength routing elements are provided. Each retroreflecting element is configured to retroreflect an optical ray that is orthogonal to a reference plane. A first reflective surface, such as may be provided by a mirror, is inclined with respect to the reference plane and is disposed to encounter the optical ray. The first reflective surface is also configured for rotation about an axis to multiple positions. A second reflective surface, such as may also be provided by a mirror, is inclined with respect to the first reflective surface. In at least one of the positions, the optical ray also encounters the second reflective surface.