Researchers from UC San Diego have developed RadSenNet, a new approach of sequential fusing of information from radars and cameras. The key idea of sequential fusion is to fundamentally shift the center of focus in radar-camera fusion systems from cameras to radars. This shift enables their invention (RadSegNet) to achieve all-weather perception benefits of radar sensing. Keeping radars as the primary modality ensures reliability in all situations including occlusions, longrange and bad weather.

The widespread adoption of visible light communication (VLC) systems based on light emitting diode (LED) transmitters requires the simultaneous increase in efficiency and speed of the optical source. Efficiency is measured by the external quantum efficiency while speed is quantified by the 3dB modulation bandwidth. Most research on the indium gallium nitride (InGaN) system has focused on improving the EQE because this metric, and its dependence on injection current density is an important factor for the growth of LEDs as illumination source for general lighting purposes. The modulation rate of LEDs is however poised to grow in importance due to the need to couple information processing with illumination. An LED with GHz modulation bandwidth, incorporated as light source in an optical transceiver, can enable a plethora of VLC applications: from chip-to-chip wireless communications in data centers to smart automotive lighting, from safe and RF interference-free wireless local area networks in hospitals and offices to underwater optical communications for the exploration, inspection and maintenance of offshore oil

Hyperbolic metasurfaces (HMS) merge the exotic properties of hyperbolic metamaterials with the potential for lower losses and better device coupling offered by planar metasurfaces. Despite use of single-crystalline silver (Ag), HMS remain inherently lossy, limiting potential applications. Recent work has suggested that Ag could be combined with indium gallium arsenide phosphide (InGaAsP) multiple quantum wells (MQW) to enable transparent propagation of signals through waveguides and multilayers. Described here is the first experimental demonstration of a luminescent HMS (LuHMS) based on nanostructured (NS) Ag/InGaAsP MQW.  

Today, projecting optical energy is performed using high power laser sources coupled to free-space optical systems comprised of mechanical components, moving parts, and bulk optics. Unfortunately, the application range of these legacy systems is limited by their size, weight, reliability and cost. Consequently, a substantial research effort has been directed toward the miniaturization and simplification of these systems. Recent work has focused on beam steering using phased arrays. Although optical phased arrays are an elegant non-mechanical beam steering approach, the technical and environmental challenges compared to RF systems (10,000 times smaller wavelengths and tolerances) are daunting. Multi-octave operation across the UV to LWIR regions with acceptable losses poses additional technical challenge for any optical phased array beam steering approach. For these reasons, a need exists for a non-mechanical beam steering approach that lends itself to miniaturization as well as high power ultra-wideband operation.

The ever‐increasing bandwidth requirements of modern datacenters have led researchers to propose networks based upon optical circuit switches, but these proposals face significant deployment challenges. In particular, previous proposals dynamically configure circuit switches in response to changes in workload, requiring network‐wide demand estimation, centralized circuit assignment, and tight time synchronization between various network elements— resulting in a complex and unwieldy control plane. Moreover, limitations in the technologies underlying the individual circuit switches restrict both the rate at which they can be reconfigured and the scale of the network that can be constructed; a new approach is necessary.

Brief description not available

Light emitting diodes (LEDs) directly convert electronic modulations into light signals and play an essential role in optical wireless communications links. Modulation speed and quantum efficiency of LEDs have been major challenges in achieving better optical wireless communications systems. Plasmonic structures represent a promising approach to improve both the brightness and speed of LEDs because of the delicate dynamic interactions between the light emission materials and surface plasmons. In current plasmonic-based LEDs, the plasmonic enhancement frequencies are typically misaligned with the light emission frequencies of the LEDs, significantly limiting their practical applications. Of relevance to this problem are artificially engineered materials, or metamaterials, with unique properties not attainable with naturally occurring substances. 

Semiconductor lasers generate a large amount of undesired spontaneous emission before starting lasing oscillation, which degrades their efficiency and performance substantially. Therefore, lasers that emit almost no spontaneous emission have long been sought. Such 'thresholdless lasers', - where light output versus excitation power has no obvious threshold characteristic - lasing occurs at extremely low excitation powers. These lasers' superior performance is suited to optical applications. Currently there are two main approaches to designing nanolasers. The first utilizes dielectric based structures. Dielectrics have low loss at optical frequencies. There are, however, drawbacks in using dielectric-based nanolasers: they are either large in size or their mode extends far out of the gain region, and thus they exhibit poor gain-mode overlap. The other approach uses metal in a cavity. In recent years, nanoscale metallic, plasmonic, and metallo-dielectric cavities have shown to confine light in ultra-small volumes and to improve the gain-mode spatial overlap. However, existing metal-based nanolasers require high threshold pump power because of the significant absorption loss of the metals at optical frequencies.

Brief description not available