An optical device has a housing for receiving a plurality of optical fibers adapted
to carry optical signals. A filter is disposed within the housing for transmitting
specific optical signals having a predetermined wavelength range. A first ball
lens is coupled to the housing and is positioned relative to the filter and the
optical fibers to selectively collimate and focus the optical signals. A second
ball lens is coupled to the housing and is also positioned relative to the filter
and optical fibers to selectively collimate and focus the optical signals. Both
ball lenses are optically coupled to the filter.