Interferometric determination of distance change with laser diode

• Main Authors: YVES SALVADE, MARCEL ROHNER, FRANK PRZYGODDA
• Format: Patent
• Language: Chinese; English
• Published: 24.12.2014
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; TESTING

Method for determining a change of distance to an object by interferometry with emitting measurement laser light from a laser diode, receiving at least a part of the measurement laser light, superimposing the reflected measurement laser light with a reference laser light and thereby providing at an interferometric phase and determining the change of distance to the object depending on the superimposition. The measurement laser light is emitted with low coherence and broad spectral bandwidth, wherein an emitting wavelength of the measurement laser light is fluctuating hop-freely within the spectral bandwidth causing interferometric phase fluctuations. The interferometric phase is continuously detected with a first detection rate, the detection rate being that high that the interferometric phase fluctuations are continuously incrementally tracked so that successive interferometric phase states provided by successive detections of the interferometric phase differ by a phase shift of under n. Further, the detecte