1. A light emitting device comprising:a support structure;
a light emitting diode (LED) die mounted on the support structure,
the LED die having a top surface and at least one side surface and comprising LED semiconductor layers and a transparent substrate, the substrate comprising the top surface of the LED die so that the LED die has anode and cathode electrodes on a bottom surface, the substrate being thicker than the LED semiconductor layers, wherein light emitted from the side surfaces is at least 30% of all light emitted by the LED;
a phosphor layer covering the top surface and side surfaces;
a reflector surrounding the LED die, the reflector having curved surfaces surrounding the LED die, wherein the curved surfaces extend from a generally rectangular opening for the LED die and reflect the light from the side surfaces of the LED die to form a generally rectangular beam; and
a generally rectangular lens affixed to walls of the reflector, the lens having a generally rectangular convex surface extending toward the LED die and a flat top surface facing away from the LED die.