Abstract: A random wavelength access monochromator incorporates a pair of coaxial off-axis parabolic reflectors configured so that the spherical aberrations introduced by the reflectors cancel each other. Light enters through an entrance slit and impinges upon a first off-axis parabolic reflector that collimates the beam and directs it towards a stationary grating. The grating in turn defracts the light and directs it towards a high speed scanning mirror which reflects the defracted light onto a second off-axis parabolic reflector which in turn focuses the beam to an exit slit. Both off-axis parabolic surfaces share the same axis of revolution and the same collimated beam axis. In order to make the apparatus practical, the beam is folded twice so that the exit point is focused away from the internal path of the beam.

Abstract: A dual wavelength spectrophotometer produces a relatively small, high power, high duty cycle light spot from a single relatively low power multi-chromatic light source. A Xenon arc lamp light source is focused by an ellipsoidal mirror onto a rotating partially reflective optical chopper. The chopper comprises a wheel having mirrored segments alternately separated by transparent segments. Light reflected by the mirrored segments passes through a first monochromator which produces a first monochromatic light beam. Light transmitted through the transparent segments passes through a second monochromator and emerges as a second monochromatic light beam having a wavelength different from the wavelength of said first monochromatic light beam. The first and second monochromatic light beams are recombined into a single dual wavelength light beam that is reflected through a sample to be analyzed. Reflective front surfaces are employed throughout the system in order to minimize power loss.

Abstract: A spark gap switch is disclosed. The spark gap comprises opposite and adjacent electrodes and a trigger arrangement for triggering a discharge arc between the opposite and adjacent electrodes. The trigger arrangement includes a solid insulative material to facilitate a discharge between trigger electrodes to trigger the spark gap. The trigger arrangement is located rearwardly of the adjacent electrode to position the solid insulative material in a manner to prevent a main discharge arc affecting the structural integrity of the solid insulative material. Such an arrangement provides protection for the solid insulative material to increase lifetime of the unit and has the capability of reducing jitter.

Abstract: A high intensity light source having high repetition rate and narrow pulse-width. The light source comprises a metal casing having coaxially mounted arcing electrodes therein which utilize the capacitance of the coaxial system to charge up to the arcing potential. One electrode is electrically connected to the end wall of the casing to provide a reflected wavefront from the end wall after an arc has been struck, such wavefront serving to extinguish the arc and thus provide a sharp pulse. The lamp may be used for such areas as photochemical and photobiological research, in place of much costlier nanosecond lasers.