title: Fringe abnormality induced by the external interference effect in laser feedback.
abstract: This paper presents the abnormal phenomena of the feedback fringes detected in the primary output direction compared to those detected in the rear of the laser. These abnormalities appear as the waveform deformation or abnormal phase. Experiments and calculations are carried out to investigate the mechanisms of such phenomena. It is found that they are mainly caused by the interference effects or signal superposition, both of which are introduced by the optical elements in the external cavity. Some approaches are taken to avoid those effects. And then the normal feedback fringes are attained in different detection positions, with similar waveform and phase.
authors.affiliation: State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Shulian
authors.initials: S
authors.lastname: Zhang
authors.forename: Yidong
authors.initials: Y
authors.lastname: Tan