| Popis: |
Materials such as Si, SiGe, Ge, SiN and AlN can be used for Mid-IR (3 up to 8µm). For LWIR which ranges from 8µm to 13µm, absorption limitations define the materials which can be used, such as Ge, SiGe, chalcogenides, ZnS.... Array waveguide grating devices, with SiGe waveguides cladded by Si or Ge waveguides capped by thick SiGe layers, have been designed and fabricated. They target the simultaneous detection of several gas using arrays of QCL sources. The index difference between the core and the claddings is around 0.5 on the 3-13 µm spectral range. To increase the miniaturization, the index difference has to be increased. So by using cladding material with lower index, new platforms called “Ge on insulator” have been developed such as SiGe on SiN, Ge on SiN, Ge on AlN |
