A method of forming a semiconductor structure includes: providing an initial substrate having a first region and a second region; forming a first substrate on the initial substrate; forming a first insulating layer on the first substrate; forming a second substrate on the first insulating layer; removing the second substrate in the second region to form a second insulating layer on the first insulating layer in the second region; and forming a plurality of passive devices on the second insulating layer in the second region and forming a plurality of active devices on the second substrate in the first region.

A method of forming a semiconductor structure includes: providing an initial substrate having a first region and a second region; forming a first substrate on the initial substrate; forming a first insulating layer on the first substrate; forming a second substrate on the first insulating layer; removing the second substrate in the second region to form a second insulating layer on the first insulating layer in the second region; and forming a plurality of passive devices on the second insulating layer in the second region and forming a plurality of active devices on the second substrate in the first region.

A package assembly includes a package substrate including a first die that includes a photonic integrated circuit, a second die located on the first die, the second die including an electronic integrated circuit electrically connected to the photonic integrated circuit, and an interposer module on the package substrate, at least a portion of the interposer module being located on the first die and electrically connected to the photonic integrated circuit.

A package assembly includes a package substrate including a first die that includes a photonic integrated circuit, a second die located on the first die, the second die including an electronic integrated circuit electrically connected to the photonic integrated circuit, and an interposer module on the package substrate, at least a portion of the interposer module being located on the first die and electrically connected to the photonic integrated circuit.

A three-port silicon beam splitter chip includes an input waveguide, three output waveguides, and a coupling region disposed between the input waveguide and the output waveguides and being in a square shape. The input waveguide and the output waveguide have a same width K, where 490 nm<K<510 nm, the coupling region, the input waveguide and the output waveguide have a same thickness H, where 210 nm<H<230 nm, and the coupling region has a length L, where 1600 nm<L<2000 nm. The three-port silicon beam splitter chip of the present disclosure has a high integration degree and a small size, and is capable of improving the portability of the wavefront reconstruction device.

A three-port silicon beam splitter chip includes an input waveguide, three output waveguides, and a coupling region disposed between the input waveguide and the output waveguides and being in a square shape. The input waveguide and the output waveguide have a same width K, where 490 nm<K<510 nm, the coupling region, the input waveguide and the output waveguide have a same thickness H, where 210 nm<H<230 nm, and the coupling region has a length L, where 1600 nm<L<2000 nm. The three-port silicon beam splitter chip of the present disclosure has a high integration degree and a small size, and is capable of improving the portability of the wavefront reconstruction device.

An optical coupler includes a substrate, a mirror layer, a plurality of coupling gratings, a plurality of waveguides, and an oxide layer. The substrate includes a first surface, a second surface opposite to the first surface, and a concave portion exposed from the first surface. The mirror layer is disposed in the concave portion. The coupling gratings are disposed above the mirror layer. The waveguides are laterally aligned with the coupling gratings. The concave portion faces both the coupling gratings and the waveguides. The oxide layer is bonded on the first surface. The coupling gratings and the waveguides are disposed on the oxide layer.

An optical coupler includes a substrate, a mirror layer, a plurality of coupling gratings, a plurality of waveguides, and an oxide layer. The substrate includes a first surface, a second surface opposite to the first surface, and a concave portion exposed from the first surface. The mirror layer is disposed in the concave portion. The coupling gratings are disposed above the mirror layer. The waveguides are laterally aligned with the coupling gratings. The concave portion faces both the coupling gratings and the waveguides. The oxide layer is bonded on the first surface. The coupling gratings and the waveguides are disposed on the oxide layer.

A method of Silicon Selective Epitaxial Growth (SEG) applied to a Silicon on Insulator (SOI) wafer to provide a first region of customized thickness includes with the SOI wafer having a standard thickness, applying a hard mask to a plurality of regions of the SOI wafer including the first region; applying photo-lithography protection to cover the hard mask in all of the plurality of regions except the first region; removing the hard mask in the first region; and performing Silicon SEG in the first region to provide the customized thickness in the first region, wherein the customized thickness is greater than the standard thickness.

A photonic device for splitting optical beams includes an input port configured to receive an input beam having an input power, a power splitter including perturbation segments arranged in a first region and a second region of a guide material having a first refractive index, each segment having a second refractive index, wherein the first region is configured to split the input beam into a first beam and a second beam, wherein and the second region is configured to separately guide the first and second beams, wherein the first refractive index is greater than the second refractive index, and output ports including first and second output ports connected the power splitter to respectively receive and transmit the first and second beams.