Ultra-Compact 50 W Flat Supercontinuum Generation in Single-Stage Self-Q-Switched Fiber Laser With Photonic Crystal Fiber

Jiuru He,Rui Song,Jing Hou,Li Jiang

doi:10.1109/jphot.2022.3156105

Abstract

An all-fiber supercontinuum (SC) laser source with 50.7 W average output power and spectrum ranging from 500 nm to 2400 nm is demonstrated. With the generation of high peak power nanosecond pulses and photonic crystal fiber (PCF) in the self-Q-switched fiber laser, the output SC shows good spectral width and flatness which has a 20 dB bandwidth of 1900 nm except the 1064 nm peak. The effect of the PCF length on the spectral characteristics and output power of SC were carefully studied. To the best of our knowledge, this is the highest power of SC generated in a single-stage fiber laser with such a broadband spectrum. This ultra-compact SC generation method has the merits of simple structure, low cost and good robustness, which provide an easily available SC generation method for various practical applications.

Highlights

Supercontinuum (SC) generation is a complex process involving various nonlinear effects, such as self-phase modulation (SPM), cross phase modulation (XPM), modulation instability (MI), stimulated Raman scattering (SRS) and so on, which can strongly broaden a narrowband input spectrum to dozens or even thousands of nanometers
The creative invention of photonic crystal fiber (PCF) with controllable dispersion profiles and high nonlinearity is a significant milestone for the development of SC [7]
In Ref. [8], by pumping the PCF with a picosecond fiber in three-stage master oscillator power amplifier (MOPA) configuration, a SC with 39 W output with spectral range covering from 600 nm to beyond 1700 nm was demonstrated

Summary

INTRODUCTION

Supercontinuum (SC) generation is a complex process involving various nonlinear effects, such as self-phase modulation (SPM), cross phase modulation (XPM), modulation instability (MI), stimulated Raman scattering (SRS) and so on, which can strongly broaden a narrowband input spectrum to dozens or even thousands of nanometers. The multi-stage MOPA configuration can effectively amplify the average power of the pulsed laser seed to obtain a high power SC output, but it increases the complexity and difficulty of the system. Another common used method for SC generation is using a continuous-wave (CW) laser to pump a piece of PCF [17]-[23]. The spectral broadening toward the short wavelength side is quite difficult [17]-[20] To solve this issue, gainswitched CW fiber laser could be a strongly competing technology, which can obtain a broader SC output and has the merit of simple structure [22], [23]. To the best of our knowledge, it is the highest power of SC generated in a single-stage fiber laser with such a broadband spectrum

EXPERIMENTAL SETUP

EXPERIMENTAL RESULTS AND DISCUSSIONS

Effect of the PCF length on SC generation

CONCLUSION