Adam Lancaster

Compact Cr:ZnS channel waveguide laser operating at 2333 nm

A compact mid-infrared channel waveguide laser is demonstrated in Cr:ZnS with a view to power scaling chromium laser technology utilizing the thermo-mechanical advantages of Cr:ZnS over alternative transition metal doped II-VI semiconductor laser materials. The laser provided a maximum power of 101 mW of CW output at 2333 nm limited only by the available pump power. A maximum slope efficiency of 20% was demonstrated.

Mid-infrared laser emission from Fe:ZnSe cladding waveguides

The authors present a mid-IR depressed cladding waveguide laser in Fe:ZnSe. The laser produced a maximum output power of 76 mW at 4122 nm and laser thresholds as low as 154 mW were demonstrated. This represents a 44% reduction in threshold power compared with the bulk laser system demonstrated in this paper. The waveguide laser was found to have a narrow spectral linewidth of 6 nm FHWM compared to the 50 nm typical of bulk Fe:ZnSe lasers.

Ultrabroad Mid-Infrared Tunable Cr:ZnSe Channel Waveguide Laser

Operation of a Cr:ZnSe external-cavity waveguide laser is demonstrated with a CW tuning range of 700 nm from 2077-2777 nm (700 nm or 36 THz), the widest tuning range demonstrated by a waveguide laser. Narrow linewidths as low as 53 pm FWHM (3 GHz) are achieved and a maximum output power of 120 mW is attained at 2446 nm with over 15 mW available across the entire tunable range. A theoretical model is presented allowing the effect of changes to the system to be quantified in terms of laser performance; this allows the limitations of the architecture to be assessed. Good agreement is seen between the model and the experimental values obtained.

Power scaling of ultrafast laser inscribed waveguide lasers in chromium and iron doped zinc selenide

We report demonstration of Watt level waveguide lasers fabricated using Ultrafast Laser Inscription (ULI). The waveguides were fabricated in bulk chromium and iron doped zinc selenide crystals with a chirped pulse Yb fiber laser. The depressed cladding structure in Fe:ZnSe produced output powers of 1 W with a threshold of 50 mW and a slope efficiency of 58%, while a similar structure produced 5.1 W of output in Cr:ZnSe with a laser threshold of 350 mW and a slope efficiency of 41%. These results represent the current state-of-the-art for ULI waveguides in zinc based chalcogenides.

Operation of Ho: YAG ultrafast laser inscribed waveguide lasers

We report fabrication and operation of multi-watt level waveguide lasers utilizing holmium-doped yttrium aluminum garnet (Ho:YAG). The waveguides were fabricated using ultrafast laser inscription, which relies on a chirped pulse ytterbium fiber laser to create depressed cladding structures inside the material. A variety of waveguides were created inside the Ho:YAG samples. We demonstrate output powers of ∼2  W from both a single-mode 50 μm waveguide laser and a multimode 80 μm waveguide laser. In addition, laser action from a co-doped Yb:Ho:YAG sample under in-band pumping conditions was demonstrated.

Fe:ZnSe channel waveguide laser operating at 4122 nm

The first demonstration of a waveguide laser in Fe:ZnSe is presented. The waveguide laser produces 49 mW of output power at 4122 nm with a spectral bandwidth of 6 nm FWHM.

1.94 GHz cw modelocked ytterbium-doped bismuthate glass waveguide laser

A 1.94 GHz CW modelocked ytterbium-doped bismuthate waveguide laser is presented. The waveguide was fabricated using the ultrafast laser inscription technique. Pulse energy of 30.9 pJ and pulse duration of 1.1 ps are inferred from the spectral width.

Q-switched mode-locking of a mid-infrared Tm:YAG waveguide laser with graphene film

Wave-guiding was achieved in Tm3+ doped YAG cladding waveguide fabricated by ultrafast laser inscription. With a graphene based saturable absorber mirror, Q-switched mode-locking operation in the 2 μm spectral region was realized from the waveguide.

5.9 GHz Q-switched mode-locked mid-infrared Ho:YAG waveguide laser

A Q-Switched Mode-locked Holmium doped YAG waveguide laser is reported. With a Graphene saturable output coupler, Q-switched mode-locking operation was realized in the 2 μm spectral region, with a mode-locked repetition rate of 5.9 GHz.