Faraday effect measurements of holmium oxide (Ho₂O₃) ceramics-based magneto-optical materials, highly potential material candidates for high-energy laser Faraday isolators, are presented in this paper. Temperature dependence of the Verdet constant of nondoped Ho₂O₃ ceramics was measured for temperatures 15–305 K at $1.064~\unicode[STIX]{x03BC}\text{m}$ wavelength. The Verdet constant dispersion for wavelengths 0.5–$1~\unicode[STIX]{x03BC}\text{m}$ and $1.064~\unicode[STIX]{x03BC}\text{m}$ was measured for both nondoped Ho₂O₃ ceramics and Ho₂O₃ ceramics doped with terbium Tb³⁺ (0.2 at. %) and cerium Ce³⁺ (0.1 at. %) ions. The results suggest that the relatively low level of doping of Ho₂O₃ with these ions has no significant boosting impact on the Faraday effect. Therefore, other compositions of Ho₂O₃ ceramics-based magneto-optical materials, as well as various doping concentrations, should be further examined.

The group-delay dispersion of an optical fiber was measured with the time-of-flight method, using fingerprint-like characteristic spectra from a mode-locked fiber laser source. To determine the group-delay dispersion up to the fourth order, least-squares fitting was applied to the overall time waveform mapped on the time axis for the fingerprint- spectral broadband pulses through a long optical fiber. The analysis of all 4003 data points reduced statistical uncertainty, and provided second-, third-, and fourth-order dispersion with uncertainties of 0.02%, 0.4%, and 4%, respectively.

We present the results of performance modeling of a diode-pumped solid-state HiLASE laser designed for use in inertial fusion energy power plants. The main amplifier concept is based on a He-gas-cooled multi-slab architecture similar to that employed in Mercury laser system. Our modeling quantifies the reduction of thermally induced phase aberrations and average depolarization in Yb3C:YAG slabs by a combination of helium cryogenic cooling and properly designed (doping/width) cladding materials.