Fig. 1. Hybrid integrated laser based on flip-chip bonding^[14]. (a) Schematic of flip-chip bonding of InP semiconductor laser on a silicon photonics integrated circuit; (b) SEM image of flip-chipped laser diode; (c) experimental results of placement statistics in X and Y directions; (d) schematic of process flow

Fig. 2. Hybrid integrated laser based on micro-transfer printing^[17]. (a) Schematic of hybrid integration of Ⅲ-V optoelectronic devices on a silicon photonics wafer by micro-transfer printing in a parallel manner; (b) schematic of process flow of micro-transfer printing

Fig. 3. Microscope image of Ⅲ-V-semiconductor-based optical amplifier coupons with tethers^[19]

Fig. 4. Heterogeneously integrated laser based on bonding technology. (a) Ⅲ-V epitaxial materials heterogeneously integrated on a silicon photonics wafer via bonding^[25]; (b) SEM image of cross section of a Ⅲ-V semiconductor laser heterogeneously integrated on a SOI waveguide^[27]

Fig. 5. Optical coupling strategy of heterogeneously integrated lasers. (a) Schematic of heterogeneously integrated Ⅲ-V-on-silicon laser with light mainly confined in the silicon waveguide^[28]; (b) schematic of heterogeneously integrated Ⅲ-V-on-silicon laser with light mainly confined in the active region^[29]

Fig. 6. Performance of heterogeneously integrated lasers demonstrated by Intel^[30]. (a) Optical power in the silicon waveguide versus current characteristics of a heterogeneously integrated Ⅲ-V-on-silicon laser at different temperatures; (b) output spectra of an 8λ DFB laser array; (c) relative drift of bias current for 10 mW laser output power for 36 heterogeneously integrated Ⅲ-V-on-silicon lasers operating at 80 ℃

Fig. 7. Blanket and selective heteroepitaxy of Ⅲ-V compound semiconductor on Si. (a) Blanket heteroepitaxy; (b) selective heteroepitaxy

Fig. 8. Monolithic integration of Ⅲ-V laser heteroepitaxy on Si based on vertical epitaxy. (a)(b) Monolithic integration of GaAs-based lasers on Si via blanket heteroepitaxy and butt coupling^[48]; (c)(d) monolithic integration of GaAs-based nano-ridge lasers on Si via selective heteroepitaxy and evanescent coupling^[55-56]

Fig. 9. Ⅲ-V laser integration on Si via lateral heteroepitaxy. (a) 3D schematic of selective lateral heteroepitaxy; (b) optically-pumped Ⅲ-V laser array grown on Si^[67]; (c) Ⅲ-V photodetector array grown on Si^[68]