<p>A concentric incident pumping cavity which includes a heat sink holder(1) and a number of single emitters. Each of the single emitters has a heat sink(2) and a single LD(7) mounted on the heat sink. A number of exchangeable single emitters are packed each other to form one or more single emitter arrays. There is a hole(11) in the centre of the heat sink holder, and there are slides(14) in the heat sink holder around the central hole uniformly. The single LDs of the single emitters face the central hole when the single emitter arrays are mounted in the slides. Each of the heat sinks includes a mounting part, a matching part protruding towardsthe mounting part and packing with another heat sink, and a ladder hole(23) provided in the centre of the heat sink. The mounting part of one heat sink is matched with the inner diameter of the lager hole in the ladder hole of another heatsink. The smaller hole in the ladder hole of each of the heat sink is cascaded to form a through-hole.</p>
