Abstract: In one aspect, a method of processing a semiconductor substrate is disclosed, which comprises incorporating at least one dopant in a semiconductor substrate so as to generate a doped polyphase surface layer on a light-trapping surface, and optically annealing the surface layer via exposure to a plurality of laser pulses having a pulsewidth in a range of about 1 nanosecond to about 50 nanoseconds so as to enhance crystallinity of said doped surface layer while maintaining high above-bandgap, and in many embodiments sub-bandgap optical absorptance.

Abstract: Participatory activity carried out using electronic devices is enhanced by occupying the attention of participants who complete a task before a set completion time. For example, a request or question having an expected response time less than the remaining answer time may be provided to early-finishing participants.

Abstract: The present invention generally provides semiconductor substrates having submicron-sized surface features generated by irradiating the surface with ultra short laser pulses. In one aspect a method of processing a semiconductor substrate is disclosed that includes placing at least a portion of a surface of the substrate in contact with a fluid, and exposing that surface portion to one or more femtosecond pulses so as to modify the topography of that portion. The modification can include, e.g., generating a plurality of submicron-sized spikes in an upper layer of the surface.

Abstract: In one aspect a method of fabricating an n-doped strained germanium (Ge) film is disclosed, which includes depositing a strained Ge film on an underlying substrate, implanting at least one electron-donating dopant in the Ge film, and exposing the implanted Ge film to one or more laser pulses having a pulsewidth in a range of about 1 ns to about 100 ms so as to generate a substantially crystalline strained Ge film. In some embodiments, the pulses can cause melting followed by substantial recrystallization of at least a portion of the implanted Ge film. In some embodiments, the resultant Ge film can have a thickness in a range of about 10 nm to about 1 microns.

Abstract: In one aspect, a device for generating triplet photons is disclosed, which includes a waveguide extending from a proximal end for receiving pump radiation to a distal end through which triplet photons generated via nonlinear interaction of the pump radiation with the waveguide exit the waveguide, where the waveguide is configured such that the triplet photons generated within the waveguide reach its distal end at a rate in a range of about 0.05 triplet photons/second/mW and 0.3 triplet photons/second/mW, e.g., in a range of about 0.1 triplet photons/second/mW to about 0.2 triplet photons/second/mW.

Abstract: Participatory activity carried out using electronic devices is enhanced by occupying the attention of participants who complete a task before a set completion time. For example, a request or question having an expected response time less than the remaining answer time may be provided to early-finishing participants.

Abstract: In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns.

Abstract: In one aspect, a structure for use in transfecting cells is disclosed, which comprises a matrix supporting a plurality of cavities, each cavity having an opening characterized by a rim and an inner surface subtending and/or extending from said rim. An electrically conductive coating is disposed on a top surface of the substrate between, and connecting, the rims of the cavities. A layer of an electrically conductive material can also coat at least a portion of each cavity's inner surface. At least one dimension of each cavity is in a range of about 50 nm to about 3.5 microns, e.g., in a range of about 100 nm to about 1 micron, or in a range of about 200 nm to about 800 nm, or in a range about 200 nm to about 500 nm. In some cases, all dimensions of the cavity (e.g., X, Y, an Z-Cartesian dimensions) are in the aforementioned ranges.

Abstract: In one aspect, a method of processing a semiconductor substrate is disclosed, which comprises incorporating at least one dopant in a semiconductor substrate so as to generate a doped polyphase surface layer on a light-trapping surface, and optically annealing the surface layer via exposure to a plurality of laser pulses having a pulsewidth in a range of about 1 nanosecond to about 50 nanoseconds so as to enhance crystallinity of said doped surface layer while maintaining high above-bandgap, and in many embodiments sub-bandgap optical absorptance.

Abstract: Diffractive optical elements and methods for their fabrication are disclosed. In one aspect, a diffractive optical element is disclosed, which comprises a polymeric substrate substantially transparent to at least one electromagnetic radiation wavelength, and a plurality of metallic inclusions distributed in said polymeric substrate according to a predefined pattern such that said inclusions can collectively diffract at least a portion of incident radiation having said at least one radiation wavelength.

Abstract: In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns.

Abstract: In one aspect, a composition of matter is disclosed, which comprises a photonic crystal comprising a plurality of 2D or 3D periodically repeating structures, where the structures are configured and arranged relative to one another such that the photonic crystal exhibits a Dirac cone at the center of the Brillouin zone of its reciprocal lattice, e.g., at one frequency in the optical regime. In some embodiments, the structures are formed of a dielectric material.

Abstract: Anonymous pretesting items for subsequent presentation to participants in a group enable an instructor to validate responses and revise the items accordingly.

Abstract: In one aspect, a device for generating triplet photons is disclosed, which includes a waveguide extending from a proximal end for receiving pump radiation to a distal end through which triplet photons generated via nonlinear interaction of the pump radiation with the waveguide exit the waveguide, where the waveguide is configured such that the triplet photons generated within the waveguide reach its distal end at a rate in a range of about 0.05 triplet photons/second/mW and 0.3 triplet photons/second/mW, e.g., in a range of about 0.1 triplet photons/second/mW to about 0.2 triplet photons/second/mW.

Abstract: The present teachings are generally directed to devices and methods for triplet photons generations, and in particular to on-chip integrated sources for generating direct triplet entangled photons.

Abstract: In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns.

Abstract: Representative embodiments of a method for grouping participants in an activity include the steps of: (i) defining a grouping policy; (ii) storing, in a database, participant records that include a participant identifier, a characteristic associated with the participant, and/or an identifier for a participant's handheld device; (iii) defining groupings based on the policy and characteristics of the participants relating to the policy and to the activity; and (iv) communicating the groupings to the handheld devices to establish the groups.

Abstract: In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns.

Abstract: The present invention generally provides semiconductor substrates having submicron-sized surface features generated by irradiating the surface with ultra short laser pulses. In one aspect, a method of processing a semiconductor substrate is disclosed that includes placing at least a portion of a surface of the substrate in contact with a fluid, and exposing that surface portion to one or more femtosecond pulses so as to modify the topography of that portion. The modification can include, e.g., generating a plurality of submicron-sized spikes in an upper layer of the surface.

Abstract: Representative embodiments of a method for grouping participants in an activity include the steps of: (i) defining a grouping policy; (ii) storing, in a database, participant records that include a participant identifier, a characteristic associated with the participant, and/or an identifier for a participant's handheld device; (iii) defining groupings based on the policy and characteristics of the participants relating to the policy and to the activity; and (iv) communicating the groupings to the handheld devices to establish the groups.