A dielectric waveguide integrated plasma lamp (DWIPL) with a body comprising at least one dielectric material having a dielectric constant greater than approximately 2, and having a shape and dimensions such that the body resonates in at least one resonant mode when microwave energy of an appropriate frequency is coupled into the body. A dielectric bulb within a lamp chamber in the body contains a fill which when receiving energy from the resonating body forms a light-emitting plasma. The bulb is transparent to visible light and infrared radiation emitted by the plasma. Radiative energy lost from the plasma is recycled by reflecting the radiation from thin-film, multi-layer coatings on bulb exterior surfaces and/or lamp chamber surfaces back into the bulb. The lamp further includes two- or three-microwave probe configurations minimizing power reflected from the body back to the microwave source when the source operates: (a) at a frequency such that the body resonates in a single mode; or (b) at one frequency such that the body resonates in a relatively higher mode before a plasma is formed, and at another frequency such that the body resonates in a relatively lower order mode after the plasma reaches steady state.