A portable self-contained tooth-whitening device comprising: a compact housing structured and configured to be held in a fixed position adjacent to a human jaw during use; at least a first array of light-emitting diodes "LEDs" disposed in a first plane at a front side of the housing and arranged to deliver blue visible light with a peak intensity of 450-470nm of at least a threshold intensity to substantially all anterior surfaces of anterior maxillary teeth or anterior mandibular teeth of the human jaw, characterized in that each LED has an axis of primary focus, defined as the axis along with the LED-emitted light has the highest intensity and wherein the axes of primary focus of all LEDs of the respective arc intersect at the focal point of that arc, wherein the at least first array of LEDs forms at least two intersecting arcs (30, 40), each of which is disposed in the first plane and has its own focal point located outside the device and wherein the at least first array of LEDs comprises a plurality of four to eight inner LEDs and a plurality of two to four outer LEDs, wherein the plurality of outer LEDs of the first array forms a first outer arc having a first outer focal point, and the plurality of inner LEDs of the first array forms a first inner arc having a first inner focal point different from the first outer focal point, and wherein a distance between the first outer focal point and the device is greater than a distance between the first inner focal point and the device; at least one battery cell powering the array of LEDs; and wherein the threshold light intensity at the teeth is 13 mW/cm 2. a compact housing structured and configured to be held in a fixed position adjacent to a human jaw during use; at least a first array of light-emitting diodes "LEDs" disposed in a first plane at a front side of the housing and arranged to deliver blue visible light with a peak intensity of 450-470nm of at least a threshold intensity to substantially all anterior surfaces of anterior maxillary teeth or anterior mandibular teeth of the human jaw, characterized in that each LED has an axis of primary focus, defined as the axis along with the LED-emitted light has the highest intensity and wherein the axes of primary focus of all LEDs of the respective arc intersect at the focal point of that arc, wherein the at least first array of LEDs forms at least two intersecting arcs (30, 40), each of which is disposed in the first plane and has its own focal point located outside the device and wherein the at least first array of LEDs comprises a plurality of four to eight inner LEDs and a plurality of two to four outer LEDs, wherein the plurality of outer LEDs of the first array forms a first outer arc having a first outer focal point, and the plurality of inner LEDs of the first array forms a first inner arc having a first inner focal point different from the first outer focal point, and wherein a distance between the first outer focal point and the device is greater than a distance between the first inner focal point and the device; at least one battery cell powering the array of LEDs; and wherein the threshold light intensity at the teeth is 13 mW/cm 2.