A particle discriminator using circularly polarized light projected through a channel having target particles. Light may be propagated through the channel, with some light scattered separated into forward angle scattered light, small angle scattered light and unscattered light. The forward angle scattered light may be linearly polarized and detected. The small angle scattered light may be linearly polarized in a direction orthogonal to the direction of the polarization of the forward angle scattered light, and at least both these kinds of light may be detected. Data from these detected kinds of light may be analyzed to discriminate particles from one another.