Collective Micro-Optics Technologies for VCSEL Photonic Integration

Figure 6

Cross-sectional SEM (scanning electron microscopy) images of 20-μm-wide stripe mesa after oxidation of composition-graded digital alloy Al Ga As. Oxidation time: (a) 20, (b) 30, and (c) 45 min for a self-aligned oxide integrated lens (reprinted from [31], IEEE 2006).