High power white super-continuum fiber laser and white super-continuum beam combiner

Abstract

A high power white super-continuum (SC) fiber laser and a white SC beam combiner are demonstrated. The white SC laser structure includes a passive mode-locked seed fiber laser, master power amplifiers and the SC generation system which uses photonic crystal fiber (PCF) with small mode area as the high nonlinear medium. In this experiment, we adopt the thermally expanded core fibers technique to fabricate a high power all fiber mode field adapter (MFA) which is used to couple high power pump pulses into the PCF, and it can work successfully under the incident pulse power of 98 W with the transmission efficiency of 82%. Meanwhile, a self-made repetition frequency multiplier (RFM) is utilized to adjust the repetition frequency (RF) of pulse and control the nonlinear (NL) effects in the amplification process. Finally, a 43 W high power white SC fiber laser source is achieved, with spectrum ranging from 450 nm to 1700 nm, spectral width below 10dB flatness exceeding 1000 nm. In addition, through theoretical simulation and designed specially, a high power (7×1) white SC combiner is obtained, and its average combining efficiency is up to 87.8% with the testing source of the obtained 43 W SC.