Abstract: The present invention provides a method for monolithic integration of multiple devices on an optoelectronic substrate. The method, in a preferred embodiment, includes forming an active layer having a given wavelength over a substrate. The method further includes forming an N-type doped layer over a portion of the active layer to form first and second active regions within the active layer, the first active region having the given wavelength and the second active region having an altered wavelength different from the given wavelength. In one exemplary embodiment, the conditions used to form the N-type doped layer, for example, dopant concentration, growth rate and temperature, cause the difference in wavelength between the given wavelength and the altered wavelength.

Abstract: The present invention provides a method for monolithic integration of multiple devices on an optoelectronic substrate. The method, in a preferred embodiment, includes forming an active layer having a given wavelength over a substrate. The method further includes forming an N-type doped layer over a portion of the active layer to form first and second active regions within the active layer, the first active region having the given wavelength and the second active region having an altered wavelength different from the given wavelength. In one exemplary embodiment, the conditions used to form the N-type doped layer, for example, dopant concentration, growth rate and temperature, cause the difference in wavelength between the given wavelength and the altered wavelength.

Abstract: A wavelength demultiplexer having at least two photodetectors is disclosed. The photodetectors are arranged in sequential layers along an optical path. The photodetectors differ in bandgap, and are arranged so that the optical signal passes through relatively larger bandgap photodetectors before being received by relatively smaller bandgap detectors. Each photodetector absorbs photons within a predetermined energy range and generates a voltage as a function of the absorbed energy. The photodetectors can be used to detect, and hence demultiplex, a wavelength-division-multiplexed signal.