The creation of Si-based intersubband lasers in multiple quantum wells of Si/SiGeC, Si/ZnS, Si/Al2O3, Si/CaF2 or Si/SiO2 would have "spinoffs" in intersubband optical amplifiers, light emitting diodes, electro-optic modulators, switches, and photodetectors. SiGe/Si and SiGeC/Si quantum-cascade lasers appear feasible for 6 to 20 mu m wavelength operation. The field-tunable Si Raman laser could operate over a wavelength range of 1.45 to 1.60 mu m. A new non-cascaded intersubband laser, the Si charge-coupled laser, has a 1 V bias and a 1 mu m optical waveguide height made possible by a p-i-p-i structure with selective contacts. Silicon nano-photonic structures rely upon a silicon-on-insulator platform.