Real-time distance measurement immune from atmospheric parameters using optical frequency combs

TL;DR

This paper introduces a real-time optical frequency comb-based ranging method that compensates for atmospheric variations, enabling precise distance measurements unaffected by environmental factors like pressure, temperature, and humidity.

Contribution

It presents a novel approach using mode-locked lasers and shaped local oscillators for environment-insensitive, high-precision distance measurement over long air paths.

Findings

Achieves real-time distance measurement immune to atmospheric parameters.

Utilizes multi-wavelength interferometry with shaped local oscillators.

Potential applications in high-precision long-distance air measurements.

Abstract

We propose a direct and real-time ranging scheme using an optical frequency combs, able to compensate optically for index of refraction variations due to atmospheric parameters. This scheme could be useful for applications requiring stringent precision over a long distance in air, a situation where dispersion becomes the main limitation. The key ingredient is the use of a mode-locked laser as a precise source for multi-wavelength interferometry in a homodyne detection scheme. By shaping temporally the local oscillator, one can directly access the desired parameter (distance) while being insensitive to fluctuations induced by parameters of the environment such as pressure, temperature, humidity and CO$_2$ content.