Patent ID: 7800738

Claim:
An arrangement for distance measurements using a frequency shifted laser radiation source, said arrangement comprising: an object detection sensor; a frequency shifted feedback laser resonator having a pumped gain medium therein with a gain greater than unity so as to emit laser light having a plurality of frequency components changing with time in a chirping manner; means for splitting said emitted laser light having said plurality of frequency components changing with time in a chirping manner into an object beam for irradiating an object and a reference beam, the object sensor being adapted to receive laser light radiation coming back from an object illuminated with the object beam light and being at a distance to be determined and also being adapted to receive said reference beam via a reference path not including the object in such a manner that the laser light radiation coming back from the object and the reference beam interfere with one another on the object sensor, said interference producing a signal by the beating of a plurality of frequency components that change with time in a chirping manner and which comprise laser light radiation coming back from said object illuminated with the object beam and beating with the plurality of frequency components that change with time in a chirping manner and which comprise the reference beam received at the sensor via said reference path not including the object, the intensity of said beat signal allowing for the determination of the distance of the object in response to the intensity of said beat signal; wherein the frequency shifted feedback laser radiation source further comprises a means for injection of narrow banded, non-pumping, modulated seed laser light into the frequency shifted feedback resonator, said means for injection modulating the seed laser light such that said intensity of said beat signal is increased.