Integrated photonics circuit and method of manufacture

Abstract

An integrated photonics circuit 400 comprises a plurality of layers deposited on a substrate 430. The layers include a plurality of cladding layers 410a-c and two patterned, optically coupled, waveguide layers 420a, 420b. One of the cladding layers 410b is sandwiched between the two waveguide layers. The cladding layer sandwiched between the two waveguide layers has a thickness allowing the waveguide layers 420a, 420b to be optically coupled while allowing them to be patterned independently. A combined thickness of the two waveguide layers and the sandwiched cladding layer may be between 400nm and 1500nm. One of the waveguide layers may be thicker, thinner or the same thickness as the other and may provide high confinement and single-mode operation. The waveguide layers may be patterned to provide a grating coupler 530. The sandwiched cladding layer 410b may be an etch stop layer of a material with a relatively low etch rate compared to the etch rate of the waveguide layers. The etch stop layer may be made of silicon oxide, aluminium oxide, hafnium oxide, calcium fluoride or magnesium fluoride. Figure 5b