Abstract: A first laser beam is reflected from the front and rear surfaces of a partially silvered glass slab generating a diverging set of interference fringes which are collimated by a positive lens. A second set of fringes is generated by a second laser beam and second partially silvered glass slab and is positioned to project through the first slab and is collimated by the same positive lens. The second pattern is aligned coaxially and mutually perpendicular to the first pattern creating a rectangular parallopiped grid pattern projected upon an observed object.

Abstract: A pulsed laser densitometer system measures highly optically dense samples. A pulsed laser beam pulse is split so that part of the beam pulse is directed through an optical delay path. The delayed beam pulse is then brought into the same path as the beam pulse transmitted through the sample and both beam pulses are fed through a detector. The output of the detector contains the optical density information in the ratio of the pulse amplitude of the transmitted pulse to the delayed pulse.