Fiber-based optical self-referencing interferometry

Abstract

The invention relates to a method for optical self-referencing interferometry. It is an object of the invention to provide a fiber-optic method and a fiber-based device for self-referencing interferometry that are cost-effective to implement and ensure high mechanical stability, reproducibility, and integration capability into existing frequency comb systems. To this end, the invention proposes a method comprising the following steps: generating pulsed laser radiation whose spectrum is an optical frequency comb and comprises at least one octave, wherein the spectrum contains a first component at a first wavelength <1 and a second component at a second wavelength <2 with <2 = 2 > 1; guiding the laser radiation through a first section of a polarization-preserving optical fiber with a polarization direction aligned along a first principal axis of the optical fiber;Wavelength-selective polarization rotation of only one of the two components, preferably the second component, by 90°, so that it is subsequently guided through the first section with its polarization direction aligned along a second principal axis of the optical fiber; polarization-selective frequency doubling of only the second component in a nonlinear medium; interfering superposition of the first component and the frequency-doubled second component to generate a beat signal on a detector. The invention also relates to a device for carrying out the method.

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