Cover Story

Laser ionization mass spectrometry in supersonic beams

Roger Tembreull, Chung Hang Sin, Ho Ming Pang, and David M. Lubman

Mass spectrometry still remains one of the most powerful means of chemical analysis based upon the exact mass identification of molecular species. This identification may be based upon the parent ion or extensive fragmentation patterns... more>>

Features

Laser applications to materials and surface analysis

James E. Parks

Resonance ionization spectroscopy (RIS) is a method of analysis in which narrow-band lasers are used to ionize elements selectively and efficiently. It is the basis for several ultrasensitive elemental analysis techniques, one of which is called sputter initiated resonance ionization spectroscopy (SIRIS), now being used for materials and surface analysis. more>>


The Kerr effect

Bruce A. Garetz

In 1875, the Scotsman John Kerr discovered that transparent, amorphous substances, such as glass and many liquids, become doubly refracting while subjected to a strong electric field.1 This phenomenon became the basis for the construction of optically bistable devices and ultrafast optical shutters, and it has become valuable in the study of molecular structure and dynamics. more>>


Photothermal methods for detection of molecules in liquids

Joel M. Harris

Photothermal spectroscopic methods are based on detecting the heat deposited in a sample by absorption of radiation and subsequent nonradiative relaxation of the excited states produced. more>>