Heterostructure Light Demultiplexing Devices
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
Semiconductor heterostructures may be employed for the purpose of light demultiplexing. The structure consists of a series of potential wells at discrete energy gaps, which can be achieved by either a compositional variation or, in addition, an external electric field. Incident radiation is demultiplexed as a result of selective absorption at different wavelengths at these wells, creating carriers which can be detected from lateral conductivity. Fig. 1 shows the physical arrangement (a) and the energy diagram (b) of such a heterostructure, using the alloy InxGal-xAs as an example. The end semiconductors are GaAs (x=0, Eg=1.43 eV) on the left and InAs (x=1, Eg=0.36 eV) on the right, within which three wells are illustrated, each corresponding to a specific composition x1, x2, or x3 .