Titanium Aluminum Carbide Coated D-Shaped Fiber as Passive Saturable Absorber for Nanosecond Pulses Generation

Abstract

The saturable absorber device based on the MAX phase titanium aluminum carbide (Ti3AlC2) deposited onto D-shaped fiber has successfully activated a pulsed laser at a center wavelength of 1557 nm. The elemental composition and vibrational modes of the saturable absorber were analyzed using energy-dispersive x-ray spectroscopy and Raman spectroscopy for chemical analysis and structure imaging. Strong saturable absorption of 2% and a non-saturable absorption of 49.2% at the 1.55-µm, confirmed its ability to generate pulses in the near-infrared wavelength spectrum. The nanosecond laser owns a pulse width of 146.7 ns, a repetition rate of 3.44 MHz, and a signal-to-noise ratio of 54.4 dB. By varying the laser diode pump from 35-90 mW, a stable short-pulsed laser was generated with the highest single pulse energy of 1.57 nJ, which corresponded to the output power of 5.4 mW. This demonstration shows the potential of MAX phase Ti3AlC2 as a saturable absorber in an all fiber-based laser cavity.