Simple evanescent field sensor for NIR spectroscopy

Near-Infrared (NIR) spectroscopy is a powerful tool for chemical analysis in applications ranging from biomedicine to analysis of food products and textiles [1]. However, molar absorptivities in this spectral region are usually weak, so that high-sensitivity measurement devices are required. Optical waveguides provide for highly sensitive attenuated total reflection (ATR) spectroscopy in a robust mass-producible format, and allow for ultra-small sample volume, due to the 100 nm scale extent of the evanescent field, and the potential for lab-on-chip integration

Arbitrary single-qubit rotations on chip with twisted waveguides

Integrated photonics is a remarkable platform for the realization of quantum computations due to its flexibility and scalability. Here we propose a novel paradigm exploiting twisted waveguides as a building block for polarization-encoded quantum photonic computations on a chip. We unveil a transformation (gate) matrix in the closed form and demonstrate that twisted waveguides can implement arbitrary Bloch sphere rotations. The outcomes of this research may open a new direction in the development of quantum computing architectures on a chip.Comment: 5 pages, 3 figure