1results about How to "Realize ranging" patented technology

This invention discloses a dual-comb absolute distance measurement system based on Raman gain modulation of a single-frequency laser. The system includes an optical frequency comb, a single-frequency laser, a rare-earth-doped amplifier, an optical coupler, a wavelength division multiplexer, a Raman gain fiber, an optical circulator, an optical collimator, a target, an optical bandpass filter, and a photodetector. The single-frequency laser is split into two paths, each coupled to an amplified optical frequency comb and then into the Raman gain fiber, generating two highly coherent Raman gain modulated dual combs: a signal comb and a local oscillator comb. The signal comb is divided into two groups; one group is reflected from the target and carries distance information, coupled to the other group and then to the local oscillator comb. After aliasing is eliminated by an optical bandwidth filter, the signal is collected by the photodetector, and the phase is de-encapsulated to calculate the distance. Due to the Raman gain modulation process, simple optical longitudinal mode stabilization and carrier wavelength readout can be achieved, ultimately using interferometry to achieve nanometer-level ranging accuracy.