Yb Fiber Amplifier at 972.5 nm with Frequency Quadrupling to 243.1 nm

Abstract

We demonstrate a continuous-wave ytterbium-doped fiber amplifier which produces 6.3 W at a wavelength of 972.5 nm. We frequency quadruple this source in two resonant doubling stages to produce 530 mW at 243.1 nm. Radiation at this wavelength is required to excite the 1S-2S transition in atomic hydrogen and could therefore find application in experimental studies of hydrogen and anti-hydrogen.

A stable 2 W continuous-wave 261.5 nm laser for cooling and trapping aluminum monochloride

“…In this work, we design, construct and characterize a frequency quadrupled DUV system as a first step toward the laser cooling and trapping of aluminum monochloride (AlCl) for future studies of strongly interacting ultracold dipolar gases. Through frequency quadrupling an amplified seed laser at 1046 nm, we realize as much as ∼2.75 W at 261.5 nm and show a stable steady state power of ∼2 W over 13 hours, furthering prior demonstrations of the power scalability of this laser system [14][15][16]. We present details for design choices alongside system performance and use this laser to perform the first spectroscopy on the AlCl A 1 Π state hyperfine structure using a cold, slow molecular beam.…”

“…As of now, Barium Borate (BBO) and Cesium Lithium Borate (CLBO) are generally considered the best options for SHG to DUV wavelengths. At the fundamental wavelength for the second cavity, 523 nm, CLBO has a ∼1.5× smaller nonlinear coefficient than BBO but doubles more efficiently due to its ∼2.5× smaller walk-off angle [16,19].…”

Cavity-enhanced deep ultraviolet laser for two-photon cooling of atomic hydrogen

“…The 243 nm laser used for the excitation of our enhancement cavity was previously described in [19], and an abbreviated schematic is shown in Fig. 1.…”

“…Therefore, the only clear avenue to increasing the intracavity power is to power scale the excitation laser. This was pursued in our previous work, where we demonstrated cw outputs of ≈ 600 mW at 243 nm [19]. Second, short wavelength optics are known to degrade when exposed to high power due to surface oxygen depletion [20] and hydrocarbon contamination [21].…”

Stable High Power deep-UV Enhancement Cavity in Ultra High Vacuum with Fluoride Coatings

“…Inspired by recent demonstrations of high-power Yb-fiber amplifiers [27,28,6] near 976 nm, the system utilizes a frequency doubled fiber-amplifier developed in collaboration with Toptica for generation of the fundamental IR radiation at 976 nm and second harmonic generation to 488 nm. The system can deliver up to 7 W of IR power and 5 W in the blue; with this, up to 1.8 W of 244 nm power can be generated in a "home-built" resonant doubling stage.…”