Nanowire photodetectors can perform exceptionally well due to their unique properties arising from the nanowire geometry. Here we report on the phenomenal responsivity and extended spectral range of scalable, vertically etched, silicon nanowire photodetector arrays defined by nanoimprint lithography. The high internal gain in these devices allows for detection at below room temperatures of subfemtowatt per micrometer visible illumination and picowatt infrared illumination resulting from band to surface state generation.

We have integrated a microfluidic magnetic trap platform with an external magnetic force microscope (MFM) cantilever. The MFM cantilever tip serves as a magnetorobotic arm that provides a translatable local magnetic field gradient to capture and move magnetic particles with nanometer precision. The MFM electronics have been programmed to sort an initially random distribution of particles by moving them within an array of magnetic trapping elements. We measured the maximum velocity at which the particles can be translated to be 2.2mm∕s±0.1mm∕s, which can potentially permit a sorting rate of approximately 5500particles∕min. We determined a magnetic force of 35.3±2.0pN acting on a 1μm diameter particle by measuring the hydrodynamic drag force necessary to free the particle. Release of the particles from the MFM tip is made possible by a nitride membrane that separates the arm and magnetic trap elements from the particle solution. This platform has potential applications for magnetic-based sorting, manipulation, and probing of biological molecules in a constant-displacement or a constant-force mode.

An InGaAs single photon avalanche detector capable of sub-Geiger mode (Photomultiplier-tube-like) operation is reported. The device achieves a stable gain at around 106. The gain fluctuation is greatly suppressed through a self-quenching effect, thus an equivalent excess noise factor as low as 1.001 is achieved. In the photon counting experiment, the device is operated in the nongated mode under a dc bias. Because of its unique characteristics of self-quenching and self-recovery, no external quenching circuit is needed. The device shows a single photon response of around 30ns and a self-recovery time of about 300ns.

Access to digital information is critical to modern defense missions. Sophisticated sensor systems are capable of acquiring and analyzing significant data, but ultimately this information must be presented to the user in a clear and convenient manner. Head-Worn Displays (HWDs) offer one means of providing this digital information. Unfortunately, conventional HWDs occupy significant volume and have serious performance limitations. To truly offer a seamless man/machine interface, the display must be able to provide a wide array of information in a manner that enhances situation awareness without interfering with normal vision. Providing information anywhere in the eye's field of view at resolutions comparable to normal vision is critical to providing meaningful information and alerts. Furthermore, the HWD must not be bulky, heavy, or consume significant power. Achieving these goals of the ideal wearable display has eluded optical designers for decades. This paper discusses the novel approach being developed under DARPA's SCENICC program to create a high resolution HWD based on using advanced contact lenses. This approach exploits the radically different concept of enhancing the eye's normal focus accommodation function to enable direct viewing of high resolution, wide field of view transparent image surfaces placed directly in front of the eye. Integrating optical components into contact lenses eliminates all of the bulky imaging optics from the HWD itself creating a high performance wearable display in a standard protective eyewear form factor. The resulting quantum advance in HWD performance will enable HWD's to expand well beyond their current limited rolls.