Precision Dimensional Metrology Based on a Femtosecond Pulse Laser

摘要: Metre is defined as the path traveled by ligh t in vacuum during time interval of 1/299 792 458 s. The optical interferometer allows a direct realization metre because it obtains displacement based on waveleng th light source use which corresponding to period interference signal. Due periodicity signal, distance can be determined accumulating phase continuously avoid 2π ambiguity problem while moving target. Conventional laser systems have been adopted this relative measurement technique for simple layout and high accuracy. Recently femtosecond pulse lasers (fs laser) has exploded its wide spectral bandwidth, short duration, frequency stability ultra-strong peak power precision spectroscopy, time-resolved measurement, micro/nano fabrication. A fs more than 105 longitudinal modes bandwidth several hundred nm wavelength. laser, comb described two measurable parameters; repetition rate carrier-offset frequency. rate, equal spacing between cavity length, caused dispersion cavity. Under stabilization frequency, are able employed scale ruler with traceability standard, cesium atomic clock. Optical generators were suggested realized generate desired welldefined wavelength locking an external tunable working wanted mode or extracting fr equency component directly from filtering amplification stages. used novel dimensional metrology due selection stability. In chapter, basic principles will introduced. And techniques using standard calibration task absolute both fundamental research industrial use.