A Q-switched fiber laser at the C + L band using an organic solution saturable absorber (SA) of dimethyl sulfoxide (DMSO) is proposed and demonstrated. The modulation depth of the DMSO-SA is measured to be 5.09%. The Q-switched operation in the laser was achieved using DMSO-SA. This Q-switched fiber laser shows an average output power of 7.9 mW with a pulse repetition rate of 21.74 kHz, a pulse width of 9  μs, and single pulse energy reaches 458.2 nJ with power set to 140 mW. Varying wavelength from 1561 to 1594 nm resulted in a stable Q-switched pulse output. The novel Q-switched laser exhibits self-starting, good stability, and high pulse energy characteristics.

Organic materials are attracting attention for their potential applications due to their large third-order optical nonlinearities. A passive fiber Q-switching laser has been demonstrated based on an erbium/ytterbium codoped amplifier and an acetone solution saturable absorber (SA). When pump power was increased from 120 to 155 mW, the repetition rate increased from 5.68 to 16.67 kHz, while the pulse width decreased from 24.1 to 15  μs. These results indicate that acetone solution can be used as an effective SA for pulsed lasers.