We demonstrate a 300 μm long silicon photonic crystal (PC) slot waveguide device for on-chip near-infrared absorption spectroscopy, based on the Beer-Lambert law for the detection of methane gas. The device combines slow light in a PC waveguide with high electric field intensity in a low-index 90 nm wide slot, which effectively increases the optical absorption path length. A methane concentrati...

We have directly imaged the spatial modes inside a one-dimensional photonic band gap device using near-field scanning optical microscopy. Our results show large scattering at the transition between waveguide modes and lattice modes, as well as increased scattering for wavelengths within the stop band. Additionally, we present preliminary results on infrared imaging of the localized mode of a de...

In this paper, we present a robust and accurate system for outdoor (as well as indoor) face recognition, based on a recently developed enhanced near-infrared (ENIR) imaging device. Using a narrow band NIR laser generator instead of LED lights for active frontal illumination, the ENIR device can provide face images of good quality even under sunlight. Experiments show that the ENIR system perfor...

Large-area, physically flexible, solution-cast photovoltaics are of urgent interest to realize low-cost solar cells. Polymer, polymer-fullerene, and polymer-nanocrystal photovoltaics absorb light only to wavelengths as long as 750 nm, with the exception of one recent report out to 1000 nm. Half of the sun’s power spectrum lies beyond 700 nm; one third beyond 1000 nm; and infrared emitters of gr...

PbS nanocrystal nc-PbS -C60 photovoltaic devices are demonstrated, in which nc-PbS function as electron donors, showing infrared photosensitivity up to 1600 nm. Annealing nc-PbS is proved to remove capping oleic acid ligands, studied using x-ray photoelectron spectroscopy, significantly improving the short circuit current, open circuit voltage, and fill factor. The device performance is rationa...

The identification and quantification of atoms, molecules, or ions concentrations in gaseous samples are in great demand for medical, environmental, industrial, law enforcement and national security applications. These applications require in situ, highresolution, non-destructive, sensitive, miniature, inexpensive, rapid detection, remotely accessed, real time and continuously operating chemica...

A new type of infrared imaging bolometer, known as the infrared imaging video bolometer ~IRVB! has been under development at the National Institute of Fusion Science ~NIFS! over the last year. A prototype of this diagnostic has been designed and constructed at NIFS and installed on the large helical device ~LHD! and successfully operated. This diagnostic utilizes a 6639030.001 mm gold foil moun...

My current research portfolio consists of work ranging from nanoscale electro‐optic modulators to 40 square meter hybrid solar energy systems. A common theme that cuts across this 10 order of magnitude change in length scale is the coupling of fundamental optical materials and device physics to emerging applications with significant impact. The Photonic Materials and Device Lab (PMDL) is consta...

Introduction. Near Infrared Spectroscopy (NIRS) is one of the biophotonic techniques which can be used to monitor oxygenation and haemodynamics in a variety of human tissues, including skeletal muscle. Due to the differing light absorption properties of oxygenated haemoglobin (Hb02) and deoxygenated haemoglobin (HHb), in the near-infrared range of the electromagnetic spectrum (see Figure 1), sh...

Existing large scale display systems generally adopt an indirect approach to user interaction. An alternative to the standard desktop-oriented devices, such as the computer mouse to control large wall-sized displays, can be considered in improving user-efficiency. By using an infrared laser pointer and an infrared tracking device, a more direct interaction with the large display can be achieved...