Patent ID: 8687173

Claim:
A method for determining a measured distance between an output of a measuring device and an object comprising the steps of: producing a first light beam having a first frequency from a first laser source and a second light beam having a second frequency from a second laser source; chirping up the first frequency at a first rate as the second frequency is chirped down at a second rate; the first rate and the second rate being different rates; chirping up the second frequency at the second rate as the first frequency is chirped down at the first rate; combining the first light beam and the second light beam using a combining coupler; directing the combined light beam path toward the object; receiving a reference path light beam for each light beam receiving a target-reflected signal path light beam from said each light beam; delivering the reference path light beam and the target-reflected signal, to a single detector; and mixing the reference path light beam and the target-reflected signal path light beam to generate two different beat frequencies that are proportional to the measured distance, the two beat frequencies being detected by the single detector.