In a study published in Optics Express, a research group led by Prof. PAN Qikun from Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) of the Chinese Academy of Sciences (CAS) proposed a pulse high energy Fe: ZnSe laser pumped by Q-switched Er: YAG laser.

Mid-infrared laser has board application in multiple fields. Uniformly doped Fe: ZnSe crystals have demonstrated enhanced gain quality within the mid-infrared wavelength range. Fe: ZnSe lasers offer unique advantages making them indispensable over other mid-infrared lasers in terms of low cost, friendly environment, compact size, huge energy, and high power.

Currently, Er:YAG laser is widely employed as pump lasers for Fe: ZnSe laser. Er: YAG lasers offer a more compact size and environmentally friendly characteristics. In this work, the Fe: ZnSe laser is pumped by an Er: YAG laser with flashlamp pumping in single pulse mode.

In order to mitigate the trailing and extract the sharp of the Er: YAG laser, the researchers to optimize the experimental setup of the Q-switched Er: YAG laser and match the resonant laser and chopper in the cavity at the spatial and temporal. At room temperature, significant improvements were achieved in the output energy and efficiency of short-pulse Fe: ZnSe lasers.

The single pulse maximum energy of Fe: ZnSe laser is 10mJ with the pulse width of 80ns, slope efficiency of 35%, and wavelength of 4.4μm at room temperature. The wavelength of Fe: ZnSe laser has red shift as the temperature rises. Additionally, the directly Q-switched Fe: ZnSe laser by optical chopper is studied which is pumped by a free-running Er: YAG laser. The researchers obtained 2.7mJ mid-infrared laser with the pulse width of 200ns at 80K through this directly mechanical Q-switched Fe: ZnSe laser.

Further, we believe that this study makes a significant contribution to the literature because this research results could promote the development of pulse mid-infrared solid stater Fe: ZnSe laser.