Abstract: A compact metal bellows preferably for converting pressure changes into lar motion, has alternating inner and outer welds accomplished by a laser weld technique. An inner weld fixture is provided for deflecting a portion of the bellows away from the very small beam spot of the laser weld process.The compact metallic bellows of the present invention is particularly adapted for fitting into a small space and taking advantage of its equal free length and solid length to provide a spring force equal the sum of the spring force of each of the several metallic diaphragms.

Abstract: A laser calorimeter which operates by absorbing the energy of a laser beam directed through a lens at the front of the calorimeter. The calorimeter contains a absorbing medium with high absorbance characteristics at the laser wavelength in question. The absorbed laser energy is converted to heat. The device has a means for measuring the changes in temperature of the absorbing medium as well as a means for measuring the changes in pressure inside the calorimeter chamber. The absorbing medium is typically a liquid which also demonstrates preferable heat transfer characteristics. This in turn affords greater precision and a faster response time of the calorimeter when measuring the laser energy. A typical medium for such a device is a dimethylformamide solution which has extremely good absorbance characteristics for an optical path length of 0.015 inches at a laser wavelength of 1.064 microns.