A thermal stabilization system for a packaged diode laser. An outer thermoelectric cooler (TEC) stabilizes the temperature of the laser package and an inner TEC stabilizes the temperature of the laser diode element of the packaged laser. The inner and outer TECs may be controlled by electronics which is also stabilized in temperature, for example using resistive heating. The packaged laser may be mounted on a heat spreader mounted on the outer TEC and may be surrounded by an insulated covering on all sides other than the surface mounted on the heat spreader. There may also be a thermally conductive cap over the packaged laser, with the insulation arranged outside the cap if both are present.