We report the growth of titanium nitride microcolumns under multipulse Nd:yttrium aluminum garnet ( 1.064 m, ∼ 300 ns, 30 kHz) laser irradiation of titanium targets in nitrogen atmosphere. The laser intensity value was chosen below the single-pulse melting threshold of titanium. The evolution with the number of laser pulses of the target morphology, crystalline state, and chemical composition a...

Laser-induced fluorescence has been used to measure tissue levels of chloroaluminum sulfonated phthalocyanine in vivo in an implanted ham ster cheek pouch carcinoma tumor model. The drug was excited at 610 nm via a pulsed nitrogen laser-pumped dye laser, and fluorescence intensity was monitored at 684 nm for up to 30 days after drug administration. Data were acquired noninvasively with high tem...

Stimulated emission is the process fundamental to laser operation, thereby producing coherent photon output. Despite negatively charged nitrogen-vacancy (NV-) centres being discussed as a potential laser medium since the 1980s, there have been no definitive observations of stimulated emission from ensembles of NV- to date. Here we show both theoretical and experimental evidence for stimulated e...

Sample throughput has been increased in many areas of proteomics, but the last significant advance in lasers used for matrix-assisted laser desorption/ionization (MALDI) was the introduction of cartridge-type N2 lasers (337 nm, 4-ns pulse widths, 1-30-Hz repetition rates) more than a decade ago. This report describes the application of a 1-kHz repetition rate Nd:YAG laser (355 nm, <500-ps pulse...

Leaf-like nanostructures with nanoscale apex are induced on dielectric target surfaces by high-repetition-rate femtosecond laser irradiation in ambient conditions. We have recently developed this unique technique to grow leaf-like nanostructures with such interesting geometry without the use of any catalyst. It was found to be possible only in the presence of background nitrogen gas flow. In th...

This article describes a gas monitoring system for detecting nitrous oxide (N2O) gas using a compact mid-infrared laser source based on difference-frequency generation in a quasi-phase-matched LiNbO3 waveguide. We obtained a stable output power of 0.62 mW from a 4.6-μm-band continuous-wave laser source operating at room temperature. This laser source enabled us to detect atmospheric N2O gas at ...

An intracavity water vapor cell in conjunction with a CO laser was used to measure experimentally the absorptive losses introduced for nineteen of the laser emission lines. The results indicated that the existing theoretical models are inadequate for predicting actual absorptance values for water vapor partial pressures in excess of 100 Torr. The accepted spectral location of at least one water...

Nitrogen-doped graphene quantum dots (N-GQDs) were fabricated by microwave-assisted hydrothermal technique. The optical properties of the N-GQDs were studied. The luminescence of the N-GQDs can be tuned by varying the excitation wavelength. Furthermore, two-photon luminescence of the N-GQDs excited by near-infrared laser can be obtained. It is shown that N-doping play a key role on two-photon l...

One of the most common methods for surgical treatment of bone metastasis is curettage. Local adjuvants are used to improve the effect of curettage in local cancer surgery and they may exerted their effects either chemically either physically; in orthopaedic oncology the most common are phenol, liquid nitrogen, laser, cement and argon beam coagulation. The purpose of this article is to review th...

The fluorescence spectrum of aqueous phenazine (PZ), an N-heterocyclic compound, shows some interesting features that indicate the formation of PZ-water complex in the excited state. Two types of complexes are postulated; Type I, formed by the association of water molecule with one of the nitrogen of PZ and Type II, formed by the association of water molecules with both the nitrogen of PZ. In a...