Radiation-Balanced Silica Fiber Amplifier

• We report what we believe to be the first radiation-balanced fiber amplifier-a device that provides optical gain while experiencing no temperature rise. The gain medium is a silica fiber with a 21-mu m-diameter core highly doped with Yb3+ (2.52 wt. %) and codoped with 2.00 wt. % Al to reduce concentration quenching. The amplifier is core pumped with 1040-nm light to create anti-Stokes fluorescence cooling and gain in the core at 1064 nm. Using a custom slow-light fiber Bragg grating sensor with mK resolution, temperature measurements are performed at multiple locations along the amplifier fiber. A 4.35-m fiber pumped with 2.62 W produced 17 dB of gain, while the average fiber temperature remained slightly below room temperature. This advancement is a fundamental step toward the creation of ultrastable lasers necessary to many applications, especially low-noise sensing and high-precision metrology.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)