This work demonstrates mode-locked pulses obtained using a polymer-coated cadmium telluride (CdTe) saturable absorber (SA). The arc-shaped fiber was fabricated using a two-step wheel-polishing process, and CdTe SA was drop-casted onto it. Then, it was overcoated with an ultraviolet (UV) cured polymer. This method enhances the fiber’s durability and protects the CdTe SA from air, dust, and moisture. The fabricated SA has a saturation intensity of 11.2 MW/cm 2 and a modulation depth of 19.8%. A stable mode-locked optical spectrum with a center wavelength of 1909.6 nm, 3-dB bandwidth of 2.9 nm, and pulse width of 1.32 ps was obtained at a threshold pump power of 398 mW. The mode-locked laser has a relatively high signal-noise ratio (SNR) of 64.9 dB. Hence, this simple polymer-coating technique enables the application of other volatile compounds as SA for future investigation.
Ahmad et al. (Tue,) studied this question.