Jacob O. Barnes

Multiwatt-level continuous-wave midwave infrared generation using difference frequency mixing in periodically poled MgO-doped lithium niobate

Over 3.5 W of continuous-wave power at 3.4 μm was obtained by single-pass difference frequency mixing of 1.064 and 1.55 μm fiber lasers in a 5 cm long periodically poled lithium niobate crystal. Good agreement was obtained between the observed temperature dependence of the generated power and the prediction from focused Gaussian beam theory.

Measuring refractive index using the focal displacement method

A simple technique is introduced for measuring the refractive index of plane-parallel samples having thickness of the order of a millimeter. The refractive index values are reported for six bulk semiconductors, each index measured at two infrared wavelengths using this method. The values are found to be within a few percent of those in literature for four semiconductors. The other two semiconductors were newly grown ternary alloys (CdMgTe and CdMnTe), for which the refractive index values have not been reported previously at the wavelengths studied here.

Hot isostatic pressing of transition metal ions into chalcogenide laser host crystals

This paper describes a technique using a hot isostatic pressing (HIP) for the diffusion of transition metal ions into chalcogenide laser host crystals. Thin layers of chromium metal are sputtered onto the surface of zinc selenide and zinc sulfide crystals before treatment in a HIP chamber. The transmissivities, excited state lifetimes, and diffusion rates are measured for various dopant concentrations. Efficiency, spectral output, and tuning data are also measured for a Cr:ZnSe laser. The diffusion rate of 5.48 × 10−8 cm2/s is two orders of magnitude faster than other techniques reported in the literature, and the sub 140 pm measured linewidth is more than 350 times smaller than what is typical of commercially available crystals. Preliminary results for Fe:ZnSe, Co:ZnSe, and Ni:ZnSe are presented as well.

Doping transition metal ions into laser host crystals by hot isostatic pressing (HIP) (Conference Presentation)

This paper describes using a hot isostatic pressing (HIP) to improve II-VI crystal characteristics and diffuse metal ions into laser host crystals. Thin layers of metal are sputtered onto the surface of zinc selenide and zinc sulfide crystals prior to being HIP treated. The pre and post treatment optical properties for these materials are measured using various methods and at a variety of dopant concentrations.

Multiwatt-level Continuous-Wave Midwave Infrared Generation using Difference Frequency Mixing in Periodically Poled Lithium Niobate

More than 2 Watts of continuous-wave external power at 3400 nm was obtained by difference frequency mixing of 1064.6 nm and 1549.8 nm fiber lasers in a periodically poled lithium niobate crystal at 50 °C.