Interaction of 10.6-µm radiation with current carriers in germanium

The absorption of 10.6-µm energy by excess carriers in germanium is used to study carrier density profiles within the bulk of intrinsic materials. Excess carriers are injected into blocks of germanium. The material is probed by an optical beam from a CO
2
laser and the energy in the exit ray is measured to determine carrier absorption. Carrier density in the material is found to correspond to two distinct patterns. The determination of carrier cross section is discussed.