Regular paper

Using dispersion-induced group delay to solve the integer ambiguity problem: a theoretical analysis

¹ Department of Mechanical Engineering, Nagaoka University of Technology, Nagaoka City, Niigata 940-2188, Japan
² School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, People’s Republic of China

^* weidong@mech.nagaokaut.ac.jp

Received: 1 April 2015
Revised: 17 June 2015

Abstract

This paper describes a novel approach for solving the integer ambiguity problem when the adjacent pulse repetition interval length (APRIL) from a femtosecond optical frequency comb (FOFC) is used as a length scale. This approach is inspired by the two-color method, which indicates that there is a one-to-one relationship between the integer part of the APRIL and the group delay distance between the two different wavelengths. Accordingly, we numerically investigate the possibility of using dispersion-induced group delay to solve the integer ambiguity problem. The results of theoretical analyses and numerical investigations demonstrate the feasibility of the proposed method. Our results should contribute toward the further development of APRIL-based length measurement methods.