Process and apparatus for absolute interferometric measurement of physical magnitudes utilizing a variable center frequency pass-band filter located downstream of a light beam source
AssigneeCise S.p.A.
InventorsValeria Gusmeroli, Mario Martinelli
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Abstract
A superluminescent source emits a wide-band light beam, that is frequency modulated by a filter with a pass band centred on a frequency that is made to vary according to a predetermined law so as to frequency modulate the light beam. Means for splitting and recombining beams determine a mutual phase shift between two components of the beam that depends on the physical magnitude to be measured and is detected by a detector as an indication of the value of the magnitude itself.
Claims11
Process for absolute interferometric measurements of physical magnitudes, comprising the steps of:
- providing a wide-band light beam from a source,
- frequency modulating said light beam by means of a pass-band filtering process located downstream of the light beam source and centered on a frequency that is made to vary with a predetermined law,
- phase shifting of components of the light beam as a function of the physical magnitude to be measured, and
- detecting and measuring the phase shift of said components of the light beam.
Apparatus for absolute interferometric measurements of physical magnitudes comprising:
- a wide-band light beam source,
- means for the frequency modulation of said light beam including a pass-band filter located downstream of the light beam source and centered on a frequency that is made to vary according to a predetermined law,
- means for splitting and recombining beams to cause the splitting of the light beam into two components with a mutual phase shift dependent on the physical magnitude to be measured, and
- a detector suitable for receiving said components of the light beam and for measuring their mutual phase shift.
Dependencies are inferred from the claim text.