Highly stable pulsed fiber laser generation modulated by chromium iodide film.

Highly stable pulsed fiber lasers are key optical components in optical communication, optical sensing, and precision micromachining systems due to the high beam quality, high peak power, and compact configurations. However, the available optical modulators in the fiber laser suffer from the operation bandwidth limitations and poor long-term physicochemical stability. Here, we have investigated the broadband nonlinear optical absorption behavior of the chromium iodide (CrI) film, which exhibits broadband saturable absorption towards the mid-infrared regime and excellent long-term stability. The conventional soliton fiber laser operating at telecom wavelength has been obtained from an Er-doped fiber laser (EDFL) utilizing CrI film with a signal-to-noise ratio (SNR) of 92.4 dB and a pulse width of 492 fs. In addition, a passively Q-switched operation around 2.8 μm has also been obtained from an Er-doped ZBLAN fiber laser (EDZFL) modulated by the CrI film with a SNR of 46.8 dB and a pulse width of 766 ns. The demonstration shows that the CrI film exhibits robust broadband optical modulation, and may make inroads for developing highly stable ultrafast optoelectronic devices.