Continuous wave Fe²⁺:ZnSe mid-IR optical fiber lasers.

Area of Science:

• Optics and Photonics
• Materials Science
• Laser Technology

Background:

• Visible and near-infrared fiber lasers are established technologies.
• Mid-infrared (mid-IR) fiber lasers face challenges in commercial availability and power output.
• Crystalline materials offer superior mid-IR performance but are difficult to fabricate into fibers.

Purpose of the Study:

• To develop a novel mid-infrared fiber laser.
• To overcome fabrication challenges for crystalline optical fibers.
• To achieve direct laser emission in the mid-infrared spectrum.

Main Methods:

• Utilized high-pressure chemical vapor deposition (HPCVD).
• Deposited iron-doped zinc selenide (Fe2+:ZnSe) into a silica optical fiber template.
• Investigated laser threshold behavior and continuous-wave (CW) emission.

Main Results:

• Successfully fabricated a solid-state fiber laser using Fe2+:ZnSe.
• Observed laser threshold behavior in the deposited structures.
• Achieved CW mid-IR laser emission with a central wavelength of 4.12 µm.

Conclusions:

• This work reports the first solid-state fiber laser with direct emission beyond 4 µm.
• The HPCVD method enables the fabrication of crystalline mid-IR fiber lasers.
• Represents a significant advancement in mid-infrared laser development.