This issue of Applied Optics features 16 papers describing chemical and environmental measurements made possible by lasers. Many of these contributions were presented at the Optical Society of America Topical Meeting on Laser Applications to Chemical and Environmental Analysis, held in Orlando, Florida, 9-11 March 1998.

The paper is devoted to the investigation of the relationship between slow integral manifolds of singularly perturbed differential equations and critical phenomena in chemical kinetics and laser models. We tried to consider different problems using the techniques of canards and black swans. The mathematical language of singular perturbations seems to apply to all critical phenomena even in the ...

Infrared lasers are ideally suited for the selective and precise removal of carious dental hard tissue while minimizing the healthy tissue loss. Since the initial investigations of Stern over 30 years ago, several unique laser applications have evolved for dentistry, namely laser ablation of dental hard tissue, caries inhibition treatments by localized surface heating, and surface conditioning ...

introduction: pulsed dye laser (pdl) has been used to treat acne lesions and scar erythema by interrupting superficial vasculature. salicylic acid chemical peels are employed chiefly due to their lipophilic, comedolytic, and anti-inflammatory properties. although studies have looked at peels and laser therapy independently in acne management, we examined these treatments in combination. our pri...

LLE Review, Volume 100 257 Introduction Large, high-power laser systems are currently under construction; such systems include the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL),1 the LMJ laser at CEA in France, and the OMEGA EP at LLE.2 These new lasers will require large amounts of neodymium phosphate laser glass, which is known to be sensitive to water.3 Wh...

BACKGROUND In chronic wounds, especially burn scars, malignant tumors can arise. However, it is rare for a subacute burn injury to change to a malignant lesion within one month. Moreover, a case of squamous cell carcinoma arising from HeNe laser therapy after a chemical burn has never been reported. CASE REPORT In this report, we examine a rare case of squamous cell carcinoma arising from HeN...

Effective germ elimination during endodontic treatment is absolutely necessary1,2 because treatment failure can often be attributed to the inadequate reduction of germs. The bacterial flora in endodontic infections is related to the flora in the oral cavity and has a bacterial population of between 102 and 107 different germs per infected root canal.3 Since mechanical preparation of the root ca...

OBJECTIVE To evaluate the efficacy of treatment of established acne scars with a sequential combination of treatment using a 1450-nm, midinfrared, nonablative diode laser with dynamic cooling spray and 30% trichloroacetic acid peels. METHODS In this prospective study 9 patients with atrophic rolling, boxcar, or both types of scars received 4 monthly treatments using a 1450-nm, midinfrared, no...

We report on experiments simulating chemical processes in early Earth’s atmosphere initiated by events with high-energy density, e.g. lightning or impact of extraterrestrial objects. Large-scale laser spark was created in the mixture of molecular gases (N2, H2O, CO or CO2) in the high-power laser laboratory PALS. Transient chemical composition was analyzed in-situ by optical emission spectrosco...

The advantages of lasers over broad-band light sources for spectroscopic measurements have long been recognized. Laser techniques offer the ability to measure the concentrations of trace species in a gas stream in `̀ real time'' with sensitivity and molecular selectivity not possible with broad band spectroscopic techniques. Until recently, the use of laser-based instruments has been largely lim...