A 3 pJ/bit free space optical interlink platform for self-powered tetherless sensing and opto-spintronic RF-to-optical transduction.

Tetherless sensors have long been positioned to enable next generation applications in biomedical, environmental, and industrial sectors. The main challenge in enabling these advancements is the realization of a device that is compact, robust over time, and highly efficient. This paper presents a tetherless optical tag which utilizes optical energy harvesting to realize scalable self-powered devices.

Evaluation of the Returned Electromagnetic Signal from Retro-reflectors in Turbid Media.

We provide first-principle theoretical and numerical simulations using the coherent Transfer Matrix Approach (TMA) to describe the behavior of the three main class of the optical beacons namely phase conjugators, reflectors, and retroreflectors within a turbid medium. Our theory describes the extraordinary enhancement (about 5 dB) offered by retroreflectors compared to reflectors in our detailed experiments and shows that they effectively act as local optical phase conjugators. Moreover, the performance of retroreflectors shows little degradation for increased light incident angles in turbid media, while the performance of reflectors degrades drastically.

Open architecture time of flight 3D SWIR camera operating at 150 MHz modulation frequency.

In the past two decades 3-D cameras have proven to be one of the next revolutions in machine vision. However, these devices are still an emerging technology with a particularly narrow set of commercially available devices. In this paper, the concept and execution of the first short wavelength infrared (SWIR) time-of-flight (ToF) 3-D camera system operating at a wavelength of 1550 nm is presented.

Molecular weight characterization of single globular proteins using optical nanotweezers.

We trap a set of molecular weight standard globular proteins using a double nanohole optical trap. The root mean squared variation of the trapping laser transmission intensity gives a linear dependence with the molecular weight, showing the potential for analysis of globular proteins. The characteristic time of the autocorrelation of the trapping laser intensity variations scales with a -2/3 power dependence with the volume of the particle.

Label-free free-solution nanoaperture optical tweezers for single molecule protein studies.

Nanoaperture optical tweezers are emerging as useful label-free, free-solution tools for the detection and identification of biological molecules and their interactions at the single molecule level. Nanoaperture optical tweezers provide a low-cost, scalable, straight-forward, high-speed and highly sensitive (SNR ∼ 33) platform to observe real-time dynamics and to quantify binding kinetics of protein-small molecule interactions without the need to use tethers or labeling. Such nanoaperture-based optical tweezers, which are 1000 times more efficient than conventional optical tweezers, have been used to trap and isolate single DNA molecules and to study proteins like p53, which has been claimed to be in mutant form for 75% of human cancers.

Playing the notes of DNA with light: extremely high frequency nanomechanical oscillations.

We use a double nanohole (DNH) optical tweezer with two trapping lasers beating to excite the vibrational modes of single-stranded DNA (ssDNA) fragments in the extremely high frequency range. We find the resonant vibration frequency of a 20 base ssDNA to be 40 GHz. We show that the change in the resonant frequency for different lengths of the DNA strand is in good agreement with one dimensional lattice vibration theory.