OPTICAL INTERFEROMETER FOR THRUST MEASUREMENTS

ALTAIR Center proposes to develop an innovative system for accurate measuring thrust performance of different structural components, including propulsion systems for micro-satellites, with micro-Newton resolution. The system designed for operation in aspace simulation chamber employs a fiber optical scheme incorporating an interferometric force sensor. A Fabry-Perot white-light interferometer used in the system operates in wide spectral range. The interferometric information delivered by the lightthrough an optical fiber can be conveniently analyzed outside the test chamber. The system exhibits high temperature stability that is achieved by employing elastic elements made of fused silica and assembled using laser welding. Among other importantadvantages of the proposed system are high stability of readings, high sensitivity and wide dynamic range (up to 100000). The readings are practically independent of radiation losses in optical elements. The technique offers high degree of universality andcan be used in many important industrial applications for measuring weak forces, low pressures, small displacements, accelerations, etc. Phase I of the project will address to demonstrating feasibility of a thrust stand based on white-light interferometricmeasurements with micro-Newton resolution and wide dynamic range. In Phase II, the prototype system will be assembled, tested and optimized with final product delivered to DoD.In addition to immediate military applications for thrust measurements, theproposed system is an excellent candidate as a product in several markets including airspace industry, transportation, power engineering, etc.