Abstract: An exemplary multi quantum well structure may include a silicon platform having a pit formed in the silicon platform, a chip positioned inside the pit, a first waveguide formed in the chip, and a second waveguide formed in the silicon platform. The pit may be defined at least in part by a sidewall and a base. The chip may include a first side and a first recess in the first side. The first side may be defined in part by a first cleaved or diced facet. The first recess may be defined in part by a first etched facet. The first waveguide may be configured to guide an optical beam to pass through the first etched facet. The second waveguide may be configured to guide the optical beam to pass through the sidewall. The second waveguide may be optically aligned with the first waveguide.

Abstract: A semiconductor laser has a mirror formed in a gain chip. The mirror can be placed in the gain chip to provide a broadband reflector to support multiple lasers using the gain chip. The mirror can also be placed in the gain chip to have the semiconductor laser be more efficient or more powerful by changing an optical path length of the gain of the semiconductor laser.

Abstract: A polarization-independent, optical circulator is formed in silicon photonics. The polarization-independent, optical circulator uses an optical splitter having two couplers and two waveguides joining the two couplers. One of the two waveguides is thinner than the other to create a large effective index difference between TE and TM modes transmitted through the one waveguide. Polarization rotators, including reciprocal and/or non-reciprocal rotators, are further used to create the optical circulator.

Abstract: A waveguide coupler includes a first waveguide and a second waveguide. The waveguide coupler also includes a connecting waveguide disposed between the first waveguide and the second waveguide. The connecting waveguide includes a first material having a first index of refraction and a second material having a second index of refraction higher than the first index of refraction.

Abstract: A semiconductor laser device is provided. The semiconductor laser device includes: a substrate having a first facet; a guiding layer having a second facet through which an output light is configured to be emitted; a bottom dielectric layer between the substrate and the guiding layer, and a top dielectric layer on the guiding layer. The second facet is at an angle relative to the first facet.

Abstract: A polarization-independent, optical circulator is formed in silicon photonics. The polarization-independent, optical circulator uses an optical splitter having two couplers and two waveguides joining the two couplers. One of the two waveguides is thinner than the other to create a large effective index difference between TE and TM modes transmitted through the one waveguide. Polarization rotators, including reciprocal and/or non-reciprocal rotators, are further used to create the optical circulator.

Abstract: A semiconductor laser device is provided. The semiconductor laser device includes: a substrate having a first facet; a guiding layer having a second facet through which an output light is configured to be emitted; a bottom dielectric layer between the substrate and the guiding layer; and a top dielectric layer on the guiding layer. The second facet is at an angle relative to the first facet.

Abstract: An exemplary multi quantum well structure may include a silicon platform having a pit formed in the silicon platform, a chip positioned inside the pit, a first waveguide formed in the chip, and a second waveguide formed in the silicon platform. The pit may be defined at least in part by a sidewall and a base. The chip may include a first side and a first recess in the first side. The first side may be defined in part by a first cleaved or diced facet. The first recess may be defined in part by a first etched facet. The first waveguide may be configured to guide an optical beam to pass through the first etched facet. The second waveguide may be configured to guide the optical beam to pass through the sidewall. The second waveguide may be optically aligned with the first waveguide.

Abstract: An optical bandpass filter includes an optical splitter having at least four ports, one of the ports being designated as an input port and one of the ports being designated as an output port. First and second reflectors couple with respective third and fourth ones of the ports. The splitter directs portions of the input light from the input port, into the third and fourth ports, such that the portions of the input light propagate toward the respective first and second reflectors. The first and second reflectors reflect light having wavelengths within a predetermined wavelength range, back toward the splitter, as wavelength-selected light, and transmit light having wavelengths that are outside of the predetermined wavelength range, away from the splitter. The splitter directs at least a portion of the wavelength-selected light that propagates back toward the splitter, into the output port, as output light.

Abstract: An exemplary multi quantum well structure may include a silicon platform having a pit formed in the silicon platform, a chip positioned inside the pit, a first waveguide formed in the chip, and a second waveguide formed in the silicon platform. The pit may be defined at least in part by a sidewall and a base. The chip may include a first side and a first recess in the first side. The first side may be defined in part by a first cleaved or diced facet. The first recess may be defined in part by a first etched facet. The first waveguide may be configured to guide an optical beam to pass through the first etched facet. The second waveguide may be configured to guide the optical beam to pass through the sidewall. The second waveguide may be optically aligned with the first waveguide.

Abstract: A semiconductor laser has a mirror formed in a gain chip. The mirror can be placed in the gain chip to provide a broadband reflector to support multiple lasers using the gain chip. The mirror can also be placed in the gain chip to have the semiconductor laser be more efficient or more powerful by changing an optical path length of the gain of the semiconductor laser.

Abstract: A waveguide mode expander couples a smaller optical mode in a semiconductor waveguide to a larger optical mode in an optical fiber. The waveguide mode expander comprises a shoulder and a ridge. In some embodiments, the ridge of the waveguide mode expander has a plurality of stages, the plurality of stages having different widths at a given cross section.

Abstract: An optical device comprises a substrate, a waveguide disposed on the substrate, and a spot size converter (SSC) disposed on the substrate. The waveguide comprises a shoulder and a ridge. The SSC comprises a shoulder and a ridge. The ridge of the waveguide is aligned to a first stage of the ridge of the SSC. The waveguide is made of a first material. The shoulder and the ridge of the SSC are made of a second material. The second material is different from the first material.

Abstract: A modulator and a capacitor are integrated on a semiconductor substrate for modulating a laser beam. Integrating the capacitor on the substrate reduces parasitic inductance for high-speed optical communication.

Abstract: Photonic rotators integrated on a substrate are disclosed for manipulating light polarization.

Abstract: A PAM (Pulse Amplitude Modulation) modulator driver is configured to receive a PAM input signal having N input amplitude levels and provide a PAM output signal having N output amplitude levels, where N is an integer. The PAM modulator driver circuit configured to electrically adjust amplitude levels in the PAM output signal.

Abstract: A photonic die includes an optical component that can emit output light. The optical component includes a substrate having a length and width that are substantially greater than a thickness thereof, the thickness defining a vertical direction. The optical component includes a vertical edge, and a reflective or antireflective coating on the vertical edge, wherein the reflective or antireflective coating includes a silicon-based material.

Abstract: An exemplary multi quantum well structure may include a silicon platform having a pit formed in the silicon platform, a chip positioned inside the pit, a first waveguide formed in the chip, and a second waveguide formed in the silicon platform. The pit may be defined at least in part by a sidewall and a base. The chip may include a first side and a first recess in the first side. The first side may be defined in part by a first cleaved or diced facet. The first recess may be defined in part by a first etched facet. The first waveguide may be configured to guide an optical beam to pass through the first etched facet. The second waveguide may be configured to guide the optical beam to pass through the sidewall. The second waveguide may be optically aligned with the first waveguide.

Abstract: Fabricating a multilevel composite semiconductor structure includes providing a first substrate comprising a first material; dicing a second substrate to provide a plurality of dies; mounting the plurality of dies on a third substrate; joining the first substrate and the third substrate to form a composite structure; and joining a fourth substrate and the composite structure.

Abstract: A composite device for splitting photonic functionality across two or more materials comprises a platform, a chip, and a bond securing the chip to the platform. The platform comprises a base layer and a device layer. The device layer comprises silicon and has an opening exposing a portion of the base layer. The chip, a material, comprises an active region (e.g., gain medium for a laser). The chip is bonded to the portion of the base layer exposed by the opening such that the active region of the chip is aligned with the device layer of the platform. A coating hermetically seals the chip in the platform.