Jussi-Pekka Penttinen

615 nm GaInNAs VECSEL with output power above 10 W.

A high-power optically-pumped vertical-external-cavity surface-emitting laser (VECSEL) generating 10.5 W of cw output power at 615 nm is reported. The gain mirror incorporated 10 GaInNAs quantum wells and was designed to have an emission peak in the 1230 nm range. The fundamental emission was frequency doubled to the red spectral range by using an intra-cavity nonlinear LBO crystal. The maximum optical-to-optical conversion efficiency was 17.5%. The VECSEL was also operated in pulsed mode by directly modulating the pump laser to produce light pulses with duration of ~1.5 µs. The maximum peak power for pulsed operation (pump limited) was 13.8 W. This corresponded to an optical-to-optical conversion efficiency of 20.4%.

2-µm Tm:Lu 2 O 3 ceramic disk laser intracavity-pumped by a semiconductor disk laser

A proof-of-principle study of a 1.97-µm Tm:Lu2O3 ceramic disk laser, intracavity pumped by a 1.2-µm semiconductor disk laser, is presented. The demonstrated concept allows for improved pump absorption and takes advantage of the broad wavelength coverage provided by semiconductor disk laser technology. For thin disk lasers the small thickness of the gain element typically leads to inefficient pump light absorption. This problem is usually solved by using a complex multi-pass pump arrangement. In this study we address this challenge with a new laser concept of an intracavity pumped ceramic thin disk laser. The output power at 1.97 µm was limited to 250 mW due to heat spreader-less mounting scheme of the ceramic gain disk.

AlInP-based rolled-up microtube resonators with colloidal nanocrystals operating in the visible spectral range

We report on the realization of AlInP rolled-up microtubes that can be used as high refractive index optical resonators operating in the visible spectral range down to a wavelength of at least 530 nm. Furthermore, colloidal CdSe/CdS/ZnS core-shell-shell nanocrystals were deposited close to the microtube wall by fluid filling of the microtube and subsequent evaporation of the solvent. The optical modes of the microtube resonator are excited via coupling of the nanocrystals to the evanescent fields of the modes. By embedding the nanocrystal emitters in a polymer film, an enhanced nanocrystal stability is obtained. The film is studied by the built-in refractometer of the microtube.

VECSEL systems for the generation and manipulation of trapped magnesium ions

Experiments in atomic, molecular, and optical (AMO) physics rely on lasers at many different wavelengths and with varying requirements on spectral linewidth, power, and intensity stability. Vertical external-cavity surface-emitting lasers (VECSELs), when combined with nonlinear frequency conversion, can potentially replace many of the laser systems currently in use. Here we present and characterize VECSEL systems that can perform all laser-based tasks for quantum information processing experiments with trapped magnesium ions. For photoionization of neutral magnesium, 570.6

InGaAs-QW VECSEL emitting >1.300-nm via intracavity Raman conversion

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Hybrid systems of AlInP microdisks and colloidal CdSe nanocrystals showing whispering-gallery modes at room temperature

nm light is generated with an intracavity frequency-doubled VECSEL containing a lithium triborate (LBO) crystal for second harmonic generation. External frequency doubling produces 285.3

GaInNAs solar cell with back surface reflector

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Towards direct emitting MECSELs in the yellow and red-orange spectral range (Conference Presentation)

nm light for resonant interaction with the

MECSELs and VECSELs for rubidium spectroscopy with direct emission around 780 nm (Conference Presentation)

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