Abstract: A photodetector device includes a plurality of Ge epilayers that are grown on a substrate and annealed in a defined temperature range. The Ge epilayers form a tensile strained Ge layer that allows the photodetector device to operate efficiently in the C-band and L-band.

Abstract: A waveguide-semiconductor coupling device includes a waveguide structure that includes a multimode interferometer (MMI) structure so as to minimize the reflections of TE modes in the coupling device. A mesa structure is coupled to the waveguide structure so as to minimize the reflections of TM modes in the coupling device.

Abstract: Methods of tuning, switching or modulating, or, in general, changing the resonance of waveguide micro-resonators. Changes in the resonance can be brought about, permanently or temporarily, by changing the size of the micro-resonator with precision, by changing the local physical structure of the device or by changing the effective and group indices of refraction of the mode in the micro-resonator. Further changing the asymmetry of the index profile around a waveguide can alter the birefringence of the waveguide and allows one to control the polarization in the waveguide. This change in index profile may be used to change the polarization dependence or birefringence of the resonators.

Abstract: A system of integrating electronic and optical functions includes an electronic chip that also includes monolithic IC electronics for performing electronic functions. Furthermore, the electronic chip includes a plurality of solder bumps for receiving input for processing. An optical chip receives an optical signal and performs optical functions on the signal, and outputs electrical signals indicative of the optical functions performed on the signal. Moreover, the optical chip includes a plurality of solder bumps for sending the electrical signals as input to the electronic chip. The solder bumps of the electronic chip and optical chip are bonded to together so that a hybrid integration is formed that separates the yield of the optical and electrical circuits forming the electronic and optical chip.

Abstract: A photonic bandgap device includes a first mirror region including alternating layers of different materials. A second mirror region includes alternating layers of different materials. An air gap cavity region is positioned between the first mirror region and second region. The air gap cavity changes its thickness when a voltage is applied so that the device is tuned to a particular resonant wavelength.

Abstract: A method of reducing the scattering losses that involves smoothing of the core/cladding interface and/or change of waveguide geometry in high refractive index difference waveguides. As an example, the SOI-based Si/SiO2 waveguides are subjected to an oxidation reaction at high temperatures, after the waveguide patterning process. By oxidizing the rough silicon core surfaces after the patterning process, the core/cladding interfaces are smoothened, reducing the roughness scattering in waveguides.

Abstract: A system for producing Erbium Oxide thin films with increased photoluminescence. The system includes a depositing stage for forming Erbium Oxide molecules by reacting Erbium sputtered atoms with O2 in a gas phase and creating the Erbium Oxide thin film by depositing the Erbium Oxide molecules on a substrate coated with Silicon Oxide. The system further includes an annealing stage for annealing the Erbium Oxide thin films by utilizing a low temperature treatment for a specified amount of time and temperature followed by a high temperature treatment for another specified amount of time and temperature, wherein the crystallinity of the thin films has improved.

Abstract: A system includes a plurality of AWGs, wherein one of the AWGs receives an input signal. The AWGS are divided amongst a first selective group of the AWGs providing even-numbered channel outputs associated with an even-numbered selection of the input signal, and a second selective group of the AWGs providing odd-numbered channel outputs associated with an odd-numbered selection of the input signal. An interleaver arrangement includes a plurality of ring structures so as to provide appropriate filtering characteristics for the even-numbered channel outputs and odd-numbered channel outputs.

Abstract: An optical grating is disposed on a waveguide to redirect light from the interior of the waveguide through the opposite side of the waveguide from the grating. In one embodiment the waveguide, the grating, and an optical sensor are combined in a single monolithic structure. In another embodiment, an absorbing layer is directly connected to the waveguide in the region of the grating. In still another embodiment, efficiency of the grating is improved by having a high index contrast between the refractive index of the grating and the refractive index of the cladding disposed over the grating, and by having an appropriately sized discontinuity in the grating.

Abstract: A system for producing Erbium Oxide thin films with increased photoluminescence. The system includes a depositing stage for forming Erbium Oxide molecules by reacting Erbium sputtered atoms with O2 in a gas phase and creating the Erbium Oxide thin film by depositing the Erbium Oxide molecules on a substrate coated with Silicon Oxide. The system further includes an annealing stage for annealing the Erbium Oxide thin films by utilizing a low temperature treatment for a specified amount of time and temperature followed by a high temperature treatment for another specified amount of time and temperature, wherein the crystallinity of the thin films has improved.

Abstract: A photodetector device includes a plurality of Ge epilayers that are grown on a substrate and annealed in a defined temperature range. The Ge epilayers form a tensile strained Ge layer that allows the photodetector device to operate efficiently in the C-band and L-band.

Abstract: A waveguide-semiconductor coupling device includes a waveguide structure that includes a multimode interferometer (MMI) structure so as to minimize the reflections of TE modes in the coupling device. A mesa structure is coupled to the waveguide structure so as to minimize the reflections of TM modes in the coupling device.

Abstract: Methods of tuning, switching or modulating, or, in general, changing the resonance of waveguide micro-resonators. Changes in the resonance can be brought about, permanently or temporarily, by changing the size of the micro-resonator with precision, by changing the local physical structure of the device or by changing the effective and group indices of refraction of the mode in the micro-resonator. Further changing the asymmetry of the index profile around a waveguide can alter the birefringence of the waveguide and allows one to control the polarization in the waveguide. This change in index profile may be used to change the polarization dependence or birefringence of the resonators.

Abstract: A solar cell that has a photoactive region; a Lambertian surface on the topside of the photoactive region; and a photonic crystal on the backside of the photoactive region.

Abstract: A multijunction solar cell comprising a silicon solar cell with a germanium solar cell formed on the backside of the silicon solar cell. The silicon solar cell and germanium solar cell are directly coupled via a p-p junction to inactivate interface dislocations. Preferably, the silicon solar cell comprises a p++ type silicon layer; an intrinsic silicon layer formed on the p++ type silicon layer; an n++ type silicon layer formed on the intrinsic type silicon layer; and a p-type silicon layer formed on the n++ type silicon layer. The germanium solar cell preferably comprises an n-type germanium layer; and a p-type germanium layer form on the n-type germanium layer. The p-type germanium layer is coupled to the p++ type silicon layer.

Abstract: An optical grating is disposed on a waveguide to redirect light from the interior of the waveguide through the opposite side of the waveguide from the grating. In one embodiment the waveguide, the grating, and an optical sensor are combined in a single monolithic structure. In another embodiment, an absorbing layer is directly connected to the waveguide in the region of the grating. In still another embodiment, efficiency of the grating is improved by having a high index contrast between the refractive index of the grating and the refractive index of the cladding disposed over the grating, and by having an appropriately sized discontinuity in the grating.

Abstract: A mode transformer that enables low-loss coupling between optical modes of two waveguides with different index difference. The mode size and the effective index are gradually changed between two waveguides to gradually transform the mode shape, size, and speed with minimum power loss. The mode transformer is useful for coupling the mode of an optical fiber waveguide with low index difference to the mode of a planar high index difference waveguide, and vice versa.

Abstract: A planar waveguide that has a graded index layer at the core/cladding interface to reduce scattering losses due to core/cladding interface roughness. The refractive index at the core/cladding interface is changed from that of the core to that of cladding gradually by having a graded index layer. The graded index layer reduces the scattering of light traveling in the waveguide by reducing the effect of the roughness at the abrupt interface between the core and the cladding. Using a proper design, the graded index layer also minimizes the modal and polarization dispersion of the optical mode traveling in the waveguide.

Abstract: Methods of tuning, switching or modulating, or, in general, changing the resonance of waveguide micro-resonators. Changes in the resonance can be brought about, permanently or temporarily, by changing the size of the micro-resonator with precision, by changing the local physical structure of the device or by changing the effective and group indices of refraction of the mode in the micro-resonator. Further changing the asymmetry of the index profile around a waveguide can alter the birefringence of the waveguide and allows one to control the polarization in the waveguide. This change in index profile may be used to change the polarization dependence or birefringence of the resonators.

Abstract: An optical switch operating with an optical pumping source. The switch includes a microcavity structure that is resonant with both the pumping source and the input optical signal. The microcavity structure includes a cavity in between two reflectors. The input optical signal is switched from one to zero, by varying the pump source intensity. The microcavity provides amplification of the pumping energy allowing for a nonlocal optical power source. In addition it also provides a way for fast optical modulation of the input optical signal using continuous wave pumping source.