Metaoptic bilens collimator for edge-emitting laser diodes

We present the design and simulation of a 1 mm thick metaoptic (MO) collimator optic for a blue edge-emitting laser (EEL) diode for applications such as AR/VR. The optic employs a modified inverse Galilean approach to both compensate for asymmetric EEL divergence and astigmatism. The compact bilens configuration uses a 1D MO diverging lens to expand the slow axis so that it matches the fast axis diameter in front of the second MO lens. The second lens is astigmatic and designed to produce a phase conjugate transfer function of the incident wavefront. The resulting (ab-initio) simulated bilens produces approximately a 750μm diameter circular, collimated beam with a calculated total collimation efficiency of 60% (simulation size limited), with a system M² ≈ 3. Additionally, we present some preliminary experimental results of the bilens fabricated with TiO₂ pillars and discuss potential improvements.