Author Affiliations
1College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China2Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Shanghai University, Shanghai 200444, Chinashow less
Fig. 1. (a) Experimental setup of the mode switchable fiber laser based on a master oscillator power amplifier scheme; (b) schematic of the intra-cavity mode switchable seed fiber laser. AIFG, acoustically induced fiber grating; RF, radio frequency; LD, laser diode; PSC, pump and signal combiner; YDF, ytterbium-doped fiber; CLS, cladding light stripper; QBH, quartz block holder; FLM, fiber loop mirror; MFA, mode field adapter; PC, polarization controller; FBG, fiber Bragg grating.
Fig. 2. (a) Transmission and reflection spectra of the few-mode FBG used in the intra-cavity mode switchable fiber oscillator; (b) transmission spectra of the AIFG under different modulation frequencies.
Fig. 3. (a) Output power of the LP01 and LP11 modes from the fiber amplifier as a function of the pump power (inset: beam profiles of the LP11 mode); (b) output spectra of the LP01 and LP11 modes under the maximum output power (inset: output spectra of the seed laser).
Fig. 4. (a) Output power of the LP01 and LP11 modes from the fiber oscillator as a function of the pump power; (b) output spectra and corresponding beam profiles of different operation modes.
Fig. 5. (a) Output power of the LP01 and LP11 modes from the amplifier as a function of the pump power (insets: mode profiles of the LP11 mode under different pump powers); (b) output spectra of the LP01 and LP11 modes under the maximum output power.
Fig. 6. (a) Switching time between the LP01 and LP11 modes of the seed laser with the AIFG outside the fiber oscillator; (b) switching time between the LP01 and LP11 modes from the amplifier with the AIFG outside the fiber oscillator.
Fig. 7. (a) Switching time between the LP01 and LP11 modes of the seed laser with the AIFG inside the fiber oscillator; (b) switching time between the LP01 and LP11 modes from the amplifier with the AIFG inside the fiber oscillator.
Fig. 8. Output power of the LP11 mode in both configurations recorded in the total duration of 10 min.