Ultrashort pulse generation using tantalum aluminum carbide as a pulse modulator

This paper investigates the use of tantalum aluminum carbide (<i>T</i> <i>a</i> ₂ <i>A</i> <i>l</i> <i>C</i>) as a passive pulse modulator for generating ultrafast mode-locked pulses in an erbium-doped fiber (EDF) laser cavity. The <i>T</i> <i>a</i> ₂ <i>A</i> <i>l</i> <i>C</i> modulator was prepared via an embedding method using polyvinyl alcohol as the host matrix, exhibiting a saturable absorption of 6.9% with a saturable intensity of 100<i>M</i> <i>W</i>/<i>c</i> <i>m</i> ². When integrated into a long EDF laser cavity, the modulator enabled the generation of a picosecond soliton pulse train. Operating within a pump range of 95.2 to 210.62 mW, the self-starting mode-locked EDF laser achieved a central wavelength of 1561.7 nm, a repetition rate of 1.866 MHz, and a pulse width of 3.80 ps. These findings demonstrate that <i>T</i> <i>a</i> ₂ <i>A</i> <i>l</i> <i>C</i> is an effective passive modulator for ultrafast laser generation through mode locking.