A smoke detector is provided and includes a housing defining a chamber receptive of ambient materials, one or more receivers disposed to receive light reflected from the chamber along one or more receiving axes, respectively, and multiple emitters disposed to emit light of multiple wavelengths, respectively, into the chamber at multiple angles relative to each of the one or more receiving axes, respectively, and a controller. The controller is configured to determine whether a current condition of the chamber should trigger an alarm based on output signals generated by the one or more receivers resulting from light emitted into the chamber by the multiple emitters being reflected toward the one or more receivers by the ambient materials.