5†µm CW Ce3+-doped chalcogenide glass fiber laser with 17% slope efficiency.

Efficient room temperature mid-infrared laser action in a Ce3+-doped chalcogenide fiber was demonstrated. The fiber had a doped selenide glass core in an undoped sulfide glass cladding. The pump source was a CW Fe2+:ZnSe laser emitting at 4.14 µm. The optimized fiber length allowed obtaining up to 7 mW of 5.06 µm output with 17% slope efficiency at room temperature.

Passively Q-switched 5-µm Ce3+-doped selenide glass laser using Fe:CdTe and Fe:CdSe as saturable absorbers.

The first, to the best of our knowledge, mid-infrared Q-switched Ce3+-doped glass laser is demonstrated. As saturable absorbers, Fe2+:CdSe and Fe2+:CdTe are used for the first time. When Q-switched by Fe:CdSe, the laser operates in a multi-pulse regime with an individual pulse width of 110 ns, centered at λ = 5.20 µm. With Fe:CdTe as saturable absorber, 1-3 giant pulses of 30 ns pulse width are generated at λ = 5.13 µm.

Mid-infrared laser performance of Ce3+-doped selenide glass.

An extensive study of a novel room-temperature mid-infrared Ce3+-doped Ge20Sb10Ga5Se65 glass laser is reported. An influence of output-coupler transmission on laser efficiency and emission spectra is investigated. Pumped by a pulsed Fe:ZnSe laser at 4.1 µm, a maximum output energy of 35 mJ is demonstrated at 5.2 µm, with a laser threshold of about 60 mJ and a slope efficiency of 21%. The tuning range of a mid-infrared Ce:glass laser is reported for the first time: with an intracavity prism, the laser is continuously tunable in the spectral range of 4.5-5.6 µm. The internal losses are determined to be below 9% per roundtrip.

Resonantly pumped Ce3+ mid-infrared lasing in selenide glass.

In high purity Ce3+-doped selenide glass pumped by a 4.08 µm Fe:ZnSe laser, 5.1-5.5 µm laser oscillations were observed. This is the first evidence of laser action corresponding to the 2F7/2→2F5/2 transition of Ce3+ ions.

Distributed Bragg reflector fiber laser directly written in a composite fiber manufactured by melting phosphate glass in a silica tube.

We demonstrate a single-frequency distributed Bragg reflector (DBR) fiber laser based on the novel erbium-doped composite fiber fabricated by melting phosphate glass in a silica tube. The fabricated composite fiber was single-mode at the wavelength of 1.55 µm; the measured cutoff wavelength was 1.4 µm. The composite fiber was photosensitive to irradiation at the wavelength of 193 nm. Using the phase mask method, the DBR fiber laser cavity with the total length of 21 mm was inscribed directly into the erbium-doped composite fiber. A stable single-frequency regime of the fabricated DBR laser at the wavelength of 1565 nm is demonstrated.

High-beam quality, high-efficiency laser based on fiber with heavily Yb(3+)-doped phosphate core and silica cladding.

We have fabricated and tested a composite fiber with an Yb(3+)-doped phosphate glass core and silica cladding. Oscillation with a slope efficiency of 74% was achieved using core pumping at 976 nm with fiber lengths of 48-90 mm in a simple laser configuration, where the cavity was formed by a high-reflectivity Bragg grating and the cleaved fiber end. The measured M(2) factors were as low as 1.05-1.22 even though the fiber was multimode at the lasing wavelength.

Phosphate-core silica-clad Er/Yb-doped optical fiber and cladding pumped laser.

We present a composite optical fiber with a Er/Yb co-doped phosphate-glass core in a silica glass cladding as well as cladding pumped laser. The fabrication process, optical properties, and lasing parameters are described. The slope efficiency under 980 nm cladding pumping reached 39% with respect to the absorbed pump power and 28% with respect to the coupled pump power. Due to high doping level of the phosphate core optimal length was several times shorter than that of silica core fibers.

Diode-Pumped Er-Yb:Glass Laser Passively Q Switched by Use of Co(2+):MgAl(2)O(4) as a Saturable Absorber.

We report on passively Q-switched operation of a diode-pumped Er-Yb:glass laser with a Co(2+):MgAl(2)O(4) plate as a saturable absorber. Optical pulses with peak power exceeding 2 kW and a pulse length of 2.3 ns have been generated. Single-longitudinal-mode Q-switched operation at 1.53 mum has been obtained by use of the Co(2+):MgAl(2)O(4) plate as an intracavity etalon. A discussion of the optimal Er(3+) concentration as well as optimization of the cavity design is included.