Abstract: In one example embodiment, an integrated silicon photonic wavelength division demultiplexer includes an input waveguide, an input port, a plurality of output waveguides, a plurality of output ports, a first auxiliary waveguide, and a plurality of auxiliary waveguides. The input waveguide may be formed in a first layer and having a first effective index n1. The input port may be optically coupled to the input waveguide. The output waveguides may be formed in the first layer and may have the first effective index n1. Each of the output ports may be optically coupled to a corresponding output waveguide. The first auxiliary waveguide may be formed in a second layer below the input waveguide in the first layer. The first auxiliary waveguide may have a second effective index n2 and may have two tapered ends, and n2 may be higher than n1.

Abstract: In an example, an Echelle grating wavelength division multiplexing (WDM) device includes a first waveguide, a slab waveguide, multiple second waveguides, an Echelle grating, and a metal-filled trench. The first waveguide includes either an input waveguide or an output waveguide. The multiple second waveguides are optically coupled to the first waveguide through the slab waveguide. The multiple second waveguides include multiple output waveguides if the first waveguide includes the input waveguide or multiple input waveguides if the first waveguide includes the output waveguide. The Echelle grating includes multiple grating teeth formed in the slab waveguide. The metal-filled trench forms a mirror at the grating teeth to reflect incident light from the first waveguide toward the multiple second waveguides or from the multiple second waveguides toward the first waveguide.

Abstract: An optical waveguide may include a silicon portion and a silicon nitride portion positioned over the silicon portion. The silicon portion may include a taper that decreases a width of the silicon portion. The optical waveguide may include a transition between a loaded single mode or multimode waveguide to a single mode waveguide. The silicon nitride portion may confine optical signals traveling through the optical waveguide in the silicon portion.

Abstract: An integrated optical component includes at least one input waveguide, at least one output waveguide; a first slab waveguide having a first refractive index, n1. The first slab waveguide may be disposed between at least one of the input waveguides and at least one of the output waveguides. The integrated optical component may further include a second slab waveguide having a second refractive index, n2. The integrated optical component may also include a third cladding slab having a third refractive index, n3. The third cladding slab may be disposed between the first slab and the second slab. The thickness of the second slab waveguide and the thickness of the third slab waveguide are adjustable to reduce a birefringence of the integrated optical component.

Abstract: An example system includes a grating coupled laser, a laser optical interposer (LOI), an optical isolator, and a light redirector. The grating coupled laser includes a laser cavity and a transmit grating optically coupled to the laser cavity. The transmit grating is configured to diffract light emitted by the laser cavity out of the grating coupled laser. The LOI includes an LOI waveguide with an input end and an output end. The optical isolator is positioned between the surface coupled edge emitting laser and the LOI. The light redirector is positioned to redirect the light, after the light passes through the optical isolator, into the LOI waveguide of the LOI.

Abstract: In an example, a system includes a grating coupled laser and a photonic integrated circuit. The grating coupled laser includes a first waveguide and a transmit grating coupler optically coupled to the first waveguide. The photonic integrated circuit includes a second waveguide and a receive grating coupler optically coupled to the second waveguide. The second grating coupler may include a negative angle grating coupler.

Abstract: A system may include a polarization rotator combiner. The polarization rotator combiner may include a first stage, a second stage, and a third stage. The first stage may receive a first component of light with a TE00 polarization and a second component of light with the TE00 polarization. The first stage may draw optical paths of the first and second components together. The second stage may receive the first component and the second component from the first stage. The second stage may convert the polarization of the second component from the TE00 polarization to a TE01 polarization. The third stage may receive the first component and the second component from the second stage. The third stage may convert polarization of the second component from the TE01 polarization to a TM00 polarization. The third stage may output the first component and output the second component.

Abstract: In an example, a photonic system includes a Si PIC with a Si substrate, a SiO2 box formed on the Si substrate, a first layer, and a second layer. The first layer is formed above the SiO2 box and includes a SiN waveguide with a coupler portion at a first end and a tapered end opposite the first end. The second layer is formed above the SiO2 box and vertically displaced above or below the first layer. The second layer includes a Si waveguide with a tapered end aligned in two orthogonal directions with the coupler portion of the SiN waveguide such that the tapered end of the Si waveguide overlaps in the two orthogonal directions and is parallel to the coupler portion of the SiN waveguide. The tapered end of the SiN waveguide is configured to be adiabatically coupled to a coupler portion of an interposer waveguide.

Abstract: A system includes a surface coupled edge emitting laser that includes a core waveguide, a fan out region optically coupled to the core waveguide in a same layer of the surface coupled edge emitting laser as the core waveguide; and a first surface grating formed in the fan out region; and a photonic integrated circuit (PIC) that includes an optical waveguide and a second surface grating formed in an upper layer of the PIC, wherein the second surface grating is in optical alignment with the first surface grating.

Abstract: A system includes a grating coupled laser and a photonic integrated circuit (PIC). The grating coupled laser includes a first waveguide and a transmit grating coupler optically coupled to the first waveguide. The PIC includes a second waveguide and a receive grating coupler optically coupled to the second waveguide. The receive grating coupler is in optical alignment with the transmit grating coupler. The receive grating coupler includes a first grating and a second grating spaced apart from and above the first grating within the PIC.

Abstract: An example system includes a grating coupled laser, a laser optical interposer (LOI), an optical isolator, and a light redirector. The grating coupled laser includes a laser cavity and a transmit grating optically coupled to the laser cavity. The transmit grating is configured to diffract light emitted by the laser cavity out of the grating coupled laser. The LOI includes an LOI waveguide with an input end and an output end. The optical isolator is positioned between the surface coupled edge emitting laser and the LOI. The light redirector is positioned to redirect the light, after the light passes through the optical isolator, into the LOI waveguide of the LOI.

Abstract: In an example, an Echelle grating wavelength division multiplexing (WDM) device includes a first waveguide, a slab waveguide, multiple second waveguides, an Echelle grating, and a metal-filled trench. The first waveguide includes either an input waveguide or an output waveguide. The multiple second waveguides are optically coupled to the first waveguide through the slab waveguide. The multiple second waveguides include multiple output waveguides if the first waveguide includes the input waveguide or multiple input waveguides if the first waveguide includes the output waveguide. The Echelle grating includes multiple grating teeth formed in the slab waveguide. The metal-filled trench forms a mirror at the grating teeth to reflect incident light from the first waveguide toward the multiple second waveguides or from the multiple second waveguides toward the first waveguide.

Abstract: In an example, a photonic system and method include a photonic integrated circuit (PIC) including a silicon (Si) waveguide and a first silicon nitride (SiN) waveguide. The system also includes an interposer including a second SiN waveguide including vertical tapers on the second SiN waveguide by increasing a thickness of the second SiN waveguide in a direction toward the first SiN waveguide to allow an adiabatic optical mode transfer and decreasing the thickness of the second SiN waveguide in a direction away from the first SiN waveguide to inhibit the optical mode transfer.

Abstract: An optical system includes a silicon (Si) substrate, a buried oxide (BOX) layer formed on the substrate, a silicon nitride (SiN) layer formed above the BOX layer, and a SiN waveguide formed in the SiN layer. In some embodiments, the optical system may additionally include an interposer waveguide adiabatically coupled to the SiN waveguide to form a SiN-interposer adiabatic coupler that includes at least the tapered section of the SiN waveguide, the optical system further including at least one of: a cavity formed in the Si substrate at least beneath the SiN-interposer adiabatic coupler or an oxide overlay formed between a top of a SiN core of the SiN waveguide and a bottom of the interposer waveguide. Alternatively or additionally, the optical system may additionally include a multimode Si—SiN adiabatic coupler that includes a SiN taper of a SiN waveguide and a Si taper of a Si waveguide.

Abstract: In an example, a photonic system includes a Si PIC with a Si substrate, a SiO2 box formed on the Si substrate, a first layer, and a second layer. The first layer is formed above the SiO2 box and includes a SiN waveguide with a coupler portion at a first end and a tapered end opposite the first end. The second layer is formed above the SiO2 box and vertically displaced above or below the first layer. The second layer includes a Si waveguide with a tapered end aligned in two orthogonal directions with the coupler portion of the SiN waveguide such that the tapered end of the Si waveguide overlaps in the two orthogonal directions and is parallel to the coupler portion of the SiN waveguide. The tapered end of the SiN waveguide is configured to be adiabatically coupled to a coupler portion of an interposer waveguide.

Abstract: An optical receiver with improved dynamic range may include at least one directional coupler having at least one input configured to couple to an optical fiber. The optical receiver may include a first signal path including a first photodetector coupled to an output of the at least one directional coupler, a first transimpedance amplifier (TIA) including an input coupled to the first photodetector, and an adder coupled to an output of the first TIA. The optical receiver may include a second signal path including a second photodetector coupled to an output of the at least one directional coupler, a second TIA including an input coupled to the second photodetector, and the adder coupled to an output of the second TIA. Further, the optical receiver may include an optical power sensing circuit coupled to at least one of the first TIA, the second TIA, and the adder.

Abstract: An integrated optical component includes at least one input waveguide, at least one output waveguide; a first slab waveguide having a first refractive index, n1. The first slab waveguide may be disposed between at least one of the input waveguides and at least one of the output waveguides. The integrated optical component may further include a second slab waveguide having a second refractive index, n2. The integrated optical component may also include a third cladding slab having a third refractive index, n3. The third cladding slab may be disposed between the first slab and the second slab. The thickness of the second slab waveguide and the thickness of the third slab waveguide are adjustable to reduce a birefringence of the integrated optical component.

Abstract: A system includes a surface coupled edge emitting laser that includes a core waveguide, a fan out region optically coupled to the core waveguide in a same layer of the surface coupled edge emitting laser as the core waveguide; and a first surface grating formed in the fan out region; and a photonic integrated circuit (PIC) that includes an optical waveguide and a second surface grating formed in an upper layer of the PIC, wherein the second surface grating is in optical alignment with the first surface grating.

Abstract: In one example embodiment, an integrated silicon photonic wavelength division demultiplexer includes an input waveguide, an input port, a plurality of output waveguides, a plurality of output ports, a first auxiliary waveguide, and a plurality of auxiliary waveguides. The input waveguide may be formed in a first layer and having a first effective index n1. The input port may be optically coupled to the input waveguide. The output waveguides may be formed in the first layer and may have the first effective index n1. Each of the output ports may be optically coupled to a corresponding output waveguide. The first auxiliary waveguide may be formed in a second layer below the input waveguide in the first layer. The first auxiliary waveguide may have a second effective index n2 and may have two tapered ends, and n2 may be higher than n1.

Abstract: An optical system includes a silicon (Si) substrate, a buried oxide (BOX) layer formed on the substrate, a silicon nitride (SiN) layer formed above the BOX layer, and a SiN waveguide formed in the SiN layer. In some embodiments, the optical system may additionally include an interposer waveguide adiabatically coupled to the SiN waveguide to form a SiN-interposer adiabatic coupler that includes at least the tapered section of the SiN waveguide, the optical system further including at least one of: a cavity formed in the Si substrate at least beneath the SiN-interposer adiabatic coupler or an oxide overlay formed between a top of a SiN core of the SiN waveguide and a bottom of the interposer waveguide. Alternatively or additionally, the optical system may additionally include a multimode Si—SiN adiabatic coupler that includes a SiN taper of a SiN waveguide and a Si taper of a Si waveguide.