Mode-Locked and Tunable 3.5 $\mu$m Fiber Laser Using an Acousto-Optic Modulator

Abstract

A mode-locked, dual-wavelength pumped 3.5 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula> m fiber laser using frequency shifted feedback utilizing an acousto-optic modulator is reported. Pulses of 3.8 ps with 9.7 nJ were obtained at a repetition rate of 37.75 MHz. The resulting peak power is 2.55 kW. An electronically wavelength swept, mid-IR interrogator is built to characterize a mid-IR fiber Bragg grating.