Abstract: An optical power transfer device includes a transmitter circuit, including a laser light source that is configured to emit coherent light responsive to operation above a lasing threshold, and is configured to emit incoherent light responsive operation below the lasing threshold. A proximity sensor circuit is coupled to the transmitter circuit and is configured to output a detection signal therefrom responsive to authentication of an optical receiver including at least one photovoltaic cell having surface area of about 4 square millimeters or less within a proximity thereof. The transmitter circuit is configured to operate the laser light source below the lasing threshold to emit the incoherent light responsive to an absence of the detection signal from the proximity sensor circuit. Related devices and methods of operation are also discussed.

Abstract: An optical power converter device includes a light source configured to emit monochromatic light, and a multi-junction photovoltaic cell including respective photovoltaic cell layers having different bandgaps and/or thicknesses. The respective photovoltaic cell layers are electrically connected to collectively provide an output voltage and are vertically stacked relative to a surface of the multi-junction photovoltaic cell that is arranged for illumination by the monochromatic light from the light source. Responsive to the illumination of the surface by the monochromatic light from the light source, the respective photovoltaic cell layers are configured to generate respective output photocurrents that are substantially equal. Related devices and methods of operation are also discussed.

Abstract: A multi-junction power converter system illuminated by an incident light source includes a multi-layer stack having a plurality of junctions defined by materials having different bandgaps, with an upper junction having a higher bandgap, and junctions therebelow having smaller bandgaps. The upper junction absorbs more of the incident light, whereas lower junctions successively absorb less of the remaining incident light. The junctions below the upper junction are supplied with additional illumination that has been reemitted from previous cells due to photon recycling. Related devices and methods of operation are also discussed.

Abstract: A staged contact, splitting blade assembly for splitting log sections into firewood having specific dimensions. The blade assembly has an entry end and an exit end. The assembly includes radial and bridging splitting blades, arranged in a geometric pattern around a linear axis. Each radial blade has a double tapered, cutting edge, facing the entry end of the assembly, and each bridging blade has a single tapered, cutting edge, facing the entry end of the assembly. Each succeeding blade is offset from the prior blade, such that a log section contacts the splitting blade assembly in the sequence a first blade, a second blade, a third blade, fourth blades, fifth blades, sixth blades and seventh blades. The bridging blades are positioned at a slight angle to the linear axis of the splitting blade assembly.

Abstract: A staged contact, splitting blade assembly for splitting log sections into firewood having specific dimensions. The blade assembly has an entry end and an exit end. The assembly includes radial and bridging splitting blades, arranged in a geometric pattern around a linear axis. Each radial blade has a double tapered, cutting edge, facing the entry end of the assembly, and each bridging blade has a single tapered, cutting edge, facing the entry end of the assembly. Each succeeding blade is offset from the prior blade, such that a log section contacts the splitting blade assembly in the sequence a first blade, a second blade, a third blade, fourth blades, fifth blades, sixth blades and seventh blades. The bridging blades are positioned at a slight angle to the linear axis of the splitting blade assembly.