HIGH ACCURACY ABSOLUTE LONG DISTANCE METROLOGY USING FEMTOSECOND LASERS: OPTICAL FREQUENCY COMBS AND SPECTRAL INTERFERENCE TECHNIQUES

摘要

At the frontiers of science and technology of HighrnAccuracy Absolute Long Distance Metrologyrn(HAALDM), femto-second based laser (FSL) systemsrnshow promise for combining incoherent time-of-flightrnabsolute distance measurement capabilities over largerndistances with coherent high resolution interferometricrnmethods. The combination of a long-range absoluterndistance measurement scheme with a method forrnsimultaneous sub-wavelength resolution is arncombination of requirements that naturally leads to arnbroadband or multi-wavelength measurement scheme.rnIn order to cover a range-to-resolution ratio of 10~8 for arndistance of tens of metres to 10~(13) for a distance ofrnthousands of kilometres, it is obvious that coherencernand stability of the optical "ruler" to be better than 8 torn13 decimal digits is required. Recent advances in opticalrnmetrology are particularly promising in this respectrnachieving 15 decimal digits in accuracy and beyondrnwith an optical frequency comb.rnHere we analyze the application of femto-second opticalrnfrequency combs to spectral techniques for HAALDMrnin satellite formation flying missions.