Abstract: The present invention is a method of fabricating a patterned device using a sacrificial spacer layer. The first step in this process is to select an appropriate substrate and form a step thereon. The sacrificial layer is then applied to the substrate and a blocking layer is deposited on the sacrificial layer. The blocking layer is etched back to define the mask for the semiconductor structure and the sacrificial layer is removed. The substrate is then etched using the gap created by removal of the sacrificial layer.

Abstract: Method to measure gain of a photonic inverter based on a semiconductor laser using two different modes of operation. In one mode, the device is operated as a photonic inverter device and in the other mode as a photogenerated current measurement device. While the device is operated in a photonic inverter mode, that is, pumped at a magnitude that supports photonic inverter operation, the optical output power is measured in the absence of an input signal and with an input signal that quenches the output of the photonic inverter. While the device is operated as a photogenerated current measurement device with an input optical signal, a reverse bias is applied to offset any forward bias induced by the injected input optical signal, the induced photocurrent is measured, and the wavelength of the input optical signal is measured.