Method for absolute length measurements and length measurement device

摘要

The method involves generating a frequency comb that is described as multiple equidistant ridgelines, and filtering out every last ridge line from the frequency comb to form a beam (S1). One of the ridge lines is filtered from the frequency comb to form another beam (S2). A non-zero frequency offset is generated between the beams, and a portion of one of the beams is transmitted to a measuring section. The beams are transmitted such that a beat signal is produced. Absolute length of the beat signal is calculated. An independent claim is also included for an absolute length measurement device.