Short-pulse generation in the 1-micron region using a neodymium-doped fiber laser with copper phthalocyanine absorber

Abstract

We employed an organic Copper Phthalocyanine (CuPc) thin film as a saturable absorber (SA) to generate Q-switched pulses at 1089.8 nm using a neodymium-doped fiber (NDF) as the gain medium. The CuPc SA demonstrated a favorable modulation depth of approximately 3.1 % in nonlinear optical transmission, enabling it to effectively modulate cavity loss, which is crucial for Q-switched laser operation. The NDFL generated stable Q-switched pulses, achieving a minimum pulse duration of 4.24 µs and a maximum repetition rate of 40.26 kHz. Operating at 1089.8 nm, the laser produced pulse energies of up to 2.4 nJ with a maximum pump power of 189.56 mW at 808 nm. The output exhibited exceptional stability, with a signal-to-background noise ratio of 41.87 dB at the fundamental frequency. This work marks the first demonstration of a CuPc-based Q-switched NDFL operating in the 1-micron wavelength region.