Lanthanide-doped upconversion-luminescent nanoparticles (UCNPs), which can be excited by near-infrared (NIR) laser irradiation to emit multiplex light, have been proven to be very useful for in vitro and in vivo molecular imaging studies. In comparison with the conventionally used down-conversion fluorescence imaging strategies, the NIR light excited luminescence of UCNPs displays high photosta...

Carbon dioxide detection has been of interest to scientists for several years due to the importance of atmospheric carbon concentrations and its effects on Earth’s climate. To help monitor and predict transport of atmospheric carbon, NASA created the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) program. Working alongside NASA, Colorado State University has developed a...

Thresholds for microcavitation of bovine and porcine melanosomes were previously reported, using single nanosecond (ns) laser pulses in the visible (532 nm) and the near-infrared (NIR) from 1000 to 1319 nm. Here, we report average radiant exposure thresholds for bovine melanosome microcavitation at additional NIR wavelengths up to 1540 nm, which range from ∼0.159 J∕cm2 at 800 nm to 4.5 J∕cm2 at...

Current techniques used to image gene expression in vivo use invasive surgical procedures or harmful gamma rays to analyze tissue. Optical imaging of tissue is difficult because the majority of light is absorbed by tissue. In the near infrared (NIR) region, however, absorption of light decreases and it is possible to “see” through tissue. Though absorption is minimal in the near infrared region...

Radiation-damaged nanodiamonds (DNDs) are potentially ideal optical contrast agents for photoacoustic (PA) imaging in biological tissues due to their low toxicity and high optical absorbance. PA imaging contrast agents have been limited to quantum dots and gold particles, since most existing carbon-based nanoparticles, including fluorescent nanodiamonds, do not have sufficient optical absorptio...

A simple, crude Jatropha curcas (JC) oil-based synthesis approach, devoid of any toxic phosphine and pyrophoric ligands, to produce size and shape tuned CdSe QDs and a further copper sulfide (Cu2S) encasing is presented. The QDs exhibited excellent photoluminescent properties with narrow band gap emission. Furthermore, the Cu2S shell rendered additional cytocompatibility and stability to the hy...

Pulse oximeters are widely used for noninvasive monitoring of oxygen saturation in arterial blood hemoglobin. We present a transmittance pulse oximetry system based on near-infrared (NIR) laser diodes (750 and 850 nm) for monitoring oxygen saturation of arterial blood hemoglobin. The pulse oximetry system is made up of the optical sensor, sensor electronics, and processing block. Also, we show ...

Recent advances in quantum technology have demonstrated the potential use of negatively charged nitrogen-vacancy (NV) centers in diamond for temperature and magnetic sensing at sub-cellular levels. Fluorescent nanodiamonds (FNDs) containing high-density ensembles of NV centers are appealing for such applications because they are inherently biocompatible and non-toxic. Here, we show that FNDs co...

A photolabile ruthenium-based complex, [Ru(bpy)2 (4AMP)2 ](PF6 )2 , (4AMP=4-(aminomethyl)pyridine) is incorporated into polyurea organo- and hydrogels via the reactive amine moieties on the photocleavable 4AMP ligands. While showing long-term stability in the dark, cleavage of the pyridine-ruthenium bond upon irradiation with visible or near-infrared irradiation (in a two-photon process) leads ...

In the first section of this Chapter, the basics of nonlinear optical (NLO) processes are systematically described. Then the generation of the visible pulse utilizing the NLO processes is described and ultrafast spectroscopy using the visible pulse is discussed. By using such short pulse, fast chemical reactions, which cannot be identified by utilizing strobe light or flash lamp, can be studied...