A multi-channel laser source, including: a bus waveguide coupled, at an output end of the bus waveguide, to an output of the multi-channel laser source; a first semiconductor optical amplifier; a first back mirror; a first wavelength-dependent coupler, having a first resonant wavelength, on the bus waveguide; a second semiconductor optical amplifier; a second back mirror; and a second wavelength-dependent coupler, on the bus waveguide, having a second resonant wavelength, different from the first resonant wavelength. In some embodiments the first semiconductor optical amplifier is coupled to the bus waveguide by the first wavelength-dependent coupler, which is nearer to the output end of the bus waveguide than the second wavelength-dependent coupler, the second semiconductor optical amplifier is coupled to the bus waveguide by the second wavelength-dependent coupler, and the first wavelength-dependent coupler is configured to transmit light, at the second resonant wavelength, along the bus waveguide.

A waveguide display element includes waveguide layers stacked on top of each other and an in-coupler associated with each waveguide layer for coupling light within a predefined wavelength band into the waveguide layer. Each of the in-couplers includes an intermediate layer arranged on the waveguide layer, the intermediate layer having intermediate layer properties. Each of the in-couplers further includes an in-coupling grating arranged on the intermediate layer, the grating having grating properties. The combination of the intermediate layer properties and grating properties of each in-coupler is different with respect to other in-couplers.

An eyepiece includes a substrate and an in-coupling grating patterned on a single side of the substrate. A first grating coupler is patterned on the single side of the substrate and has a first grating pattern. The first grating coupler is optically coupled to the in-coupling grating. A second grating coupler is patterned on the single side of the substrate adjacent to the first grating coupler. The second grating coupler has a second grating pattern different from the first grating pattern. The second grating coupler is optically coupled to the in-coupling grating.

A Dense Wavelength Division Multiplexing (DWDM) photonic integration circuit (PIC) that implements a DWDM system, such as a transceiver, is described. The DWDM PIC architecture includes photonic devices fully integrating on a single manufacturing platform. The DWDM PIC has a multi-wavelength optical laser, a quantum dot (QD) laser with integrated heterogeneous metal oxide semiconductor (H-MOS) capacitor, integrated on-chip. The multi-wavelength optical laser can be a symmetric comb laser that generates two equal outputs of multi-wavelength light. Alternatively, the DWDM PIC can be designed to interface with a stand-alone multi-wavelength optical laser that is off-chip. In some implementations, the DWDM PIC integrates multiple optimally designed photonic devices, such as a silicon geranium (SiGe) avalanche photodetector (APD), an athermal H-MOS wavelength splitter, a QD photodetector, and a heterogenous grating coupler. Accordingly, fabricating the DWDM PIC includes a unique III-V to silicon bonding process, which is adapted for its use of SiGe APDs.

A multi-channel laser source, including: a bus waveguide coupled, at an output end of the bus waveguide, to an output of the multi-channel laser source; a first semiconductor optical amplifier; a first back mirror; a first wavelength-dependent coupler, having a first resonant wavelength, on the bus waveguide; a second semiconductor optical amplifier; a second back mirror; and a second wavelength-dependent coupler, on the bus waveguide, having a second resonant wavelength, different from the first resonant wavelength. In some embodiments the first semiconductor optical amplifier is coupled to the bus waveguide by the first wavelength-dependent coupler, which is nearer to the output end of the bus waveguide than the second wavelength-dependent coupler, the second semiconductor optical amplifier is coupled to the bus waveguide by the second wavelength-dependent coupler, and the first wavelength-dependent coupler is configured to transmit light, at the second resonant wavelength, along the bus waveguide.

An eyepiece includes a substrate and an in-coupling grating patterned on a single side of the substrate. A first grating coupler is patterned on the single side of the substrate and has a first grating pattern. The first grating coupler is optically coupled to the in-coupling grating. A second grating coupler is patterned on the single side of the substrate adjacent to the first grating coupler. The second grating coupler has a second grating pattern different from the first grating pattern. The second grating coupler is optically coupled to the in-coupling grating.

A waveguide display element includes waveguide layers stacked on top of each other and an in-coupler associated with each waveguide layer for coupling light within a predefined wavelength band into the waveguide layer. Each of the in-couplers includes an intermediate layer arranged on the waveguide layer, the intermediate layer having intermediate layer properties. Each of the in-couplers further includes an in-coupling grating arranged on the intermediate layer, the grating having grating properties. The combination of the intermediate layer properties and grating properties of each in-coupler is different with respect to other in-couplers.

A multi-channel laser source, including: a bus waveguide coupled, at an output end of the bus waveguide, to an output of the multi-channel laser source; a first semiconductor optical amplifier; a first back mirror; a first wavelength-dependent coupler, having a first resonant wavelength, on the bus waveguide; a second semiconductor optical amplifier; a second back mirror; and a second wavelength-dependent coupler, on the bus waveguide, having a second resonant wavelength, different from the first resonant wavelength. In some embodiments the first semiconductor optical amplifier is coupled to the bus waveguide by the first wavelength-dependent coupler, which is nearer to the output end of the bus waveguide than the second wavelength-dependent coupler, the second semiconductor optical amplifier is coupled to the bus waveguide by the second wavelength-dependent coupler, and the first wavelength-dependent coupler is configured to transmit light, at the second resonant wavelength, along the bus waveguide.

A bichromatic grating coupler comprises a two-dimensional diffraction grating structure, including a first sub-grating having a first periodic structure and a second sub-grating having a second periodic structure. The first and second sub-gratings are superimposed with respect to each other in the diffraction grating structure. A first optical port is coupled to the diffraction grating structure along a first direction, and a second optical port is coupled to the diffraction grating structure along a second direction. The first optical port is configured to direct a first light beam having a first wavelength to the diffraction grating structure, such that the first light beam is diffracted in a first direction by the first sub-grating. The second optical port is configured to direct a second light beam having a second wavelength to the diffraction grating structure, such that the second light beam is diffracted in a second direction by the second sub-grating.

A bichromatic grating coupler comprises a two-dimensional diffraction grating structure, including a first sub-grating having a first periodic structure and a second sub-grating having a second periodic structure. The first and second sub-gratings are superimposed with respect to each other in the diffraction grating structure. A first optical port is coupled to the diffraction grating structure along a first direction, and a second optical port is coupled to the diffraction grating structure along a second direction. The first optical port is configured to direct a first light beam having a first wavelength to the diffraction grating structure, such that the first light beam is diffracted in a first direction by the first sub-grating. The second optical port is configured to direct a second light beam having a second wavelength to the diffraction grating structure, such that the second light beam is diffracted in a second direction by the second sub-grating.