The Ikeda map models a laser cavity. xₙ₊₁ = 1 + u(xₙcos tₙ − yₙsin tₙ), yₙ₊₁ = u(xₙsin tₙ + yₙcos tₙ), where tₙ = 0.4 − 6/(1+xₙ²+yₙ²). For u above ~0.6, the map exhibits chaos and a beautiful strange attractor with spiral structure.