Fig. 1. Oxide confinement VCSEL surface grating structure^[4]. (a) Cross-sectional view of surface grating; (b) vertical-sectional view of surface grating

Fig. 2. Schematic diagram of grating diffraction^[26]. (a) Multi-order diffraction; (b) 0th order diffraction

Fig. 3. High-index-contrast gratings VCSEL^[33]. (a) HCG VCSEL cross-sectional view; (b) simulation diagram of the relationship between the reflectivity of the device and the thickness (ordinate) and wavelength (abscissa) of HCG; (c) simulation diagram of the relationship among the reflectivity of the device, the thickness of the air bandgap (ordinate), and the HCG period (abscissa)

Fig. 4. Comparison of oxide pore diameter (Wo) and zinc diffusion pore diameter (Wz), as well as schematic diagram of zinc diffusion zone, oxide relief hole, and copper substrate zone^[41]

Fig. 5. Schematic diagram of 1060 nm VCSEL with transverse coupling cavity^[49]. (a) Cross section view; (b) schematic diagram of lateral resonance

Fig. 6. Schematic diagram of multi-hole aperture VCSEL^[53]

Fig. 7. Eye diagram of multi-hole aperture VCSEL with 2 μm oxidized aperture under NRZ-OOK modulation format

Fig. 8. Schematic diagram of beam-scanning VCSEL based on slow light effect^[62]

Fig. 9. Schematic diagram of multi-junction VCSEL^[64]

Fig. 10. Schematic diagram of multi-aperture VCSEL^[70]. (a) Schematic diagram of dry etching holes, oxidation, and non oxidation areas; (b) cross section diagram after dry etching and oxidation; (c) top view of multi-aperture VCSEL after metal deposition;(d) schematic diagram of deposited insulating and metal layer

Fig. 11. Diagram of multi-hole aperture VCSEL and multi-aperture VCSEL devices^[72]

Fig. 12. Relationship between the maximum output power of multi-hole aperture VCSEL and multi-aperture VCSEL and the size and quantity of oxidation^[72]. (a) Aperture is 2 μm; (b) aperture is 2.5 μm

Fig. 13. Photon crystal surface emitting laser^[13]. (a) Cross-sectional view; (b) vertical-sectional view of photon crystals