Probable drug-drug interaction between erlotinib and amiodarone causes severe neurotoxicity in a patient with advanced lung cancer.

Drug-drug interactions (DDIs) are of great concern in the treatment of cancer, especially when target therapies, such as tyrosine kinase inhibitors, are being used. Here, we report a case of probable DDI between erlotinib and amiodarone leading to severe neurotoxicity. Amiodarone inhibits P-glycoprotein (P-gp), for which erlotinib is a substrate. P-gp is an important drug transporter that is involved in limiting the blood-brain barrier penetration of erlotinib. Clinicians should be aware of emerging data characterizing the effect of the P-gp transport system on drug exposure and its potential for DDI.

Performance and wavelength tuning of green emitting terbium lasers.

Wavelength tuning experiments in the green spectral range applying Tb3+-doped LiLuF4 and Tb3+/Na+-codoped CaF2 single crystals are presented. While in the former case almost 100 mW could be obtained throughout a total range of 7 nm, the inhomogeneously broadened emission features of Tb3+ in the CaF2-matrix allowed for a continuous tuning range exceeding 10 nm. For initial characterization, free running continuous wave laser experiments using Tb3+-doped LiLuF4, Na+:CaF2, and stoichiometric TbF3 crystals were carried out resulting in efficient continuous wave laser operation in the green spectral region. The density of active centers in TbF3 is among the highest that can be obtained in solid state gain materials. Nevertheless, a slope efficiency as high as 32% was obtained from this crystal. High Tb3+-densities are essential to compensate for the adherent low absorption cross sections at useful pump-wavelengths.

Passively Q-switched Pr:YLF laser with a Co2+:MgAl2O4 saturable absorber.

We report on a 2ω-OPSL-pumped passively Q-switched Pr3+:LiYF4 laser operating at the wavelengths of 523, 607, and 640 nm. For this, we utilized a Co2+-doped MgAl2O4 (MALO) crystal as a saturable absorber in the visible range for the first time, to the best of our knowledge. In the green spectral region, the pulse duration was 210 ns with a pulse energy of 3.6 µJ and a repetition rate of 125 kHz. The minimum pulse duration of 87 ns at the highest pulse energy of 8.6 µJ was obtained at a repetition rate of 110 kHz at 607 nm. The highest Q-switched average laser power of 1.4 W was obtained at an absorbed continuous-wave pump power of 3.3 W with a slope efficiency of 47% at 640 nm. Absorption saturation measurements with Co:MALO were performed, and ground and excited state absorption cross sections in the visible spectral range were determined.

Watt-level passively Q-switched Er:Lu2O3 laser at 2.84 µm using MoS2.

Efficient diode-pumped passively Q-switched Er:Lu2O3 laser operation at 2.84 µm was realized. A few-layer MoS2 nanosheet film on a YAG substrate, was fabricated and employed as saturable absorber (SA) in a short plane-plane cavity. Under an absorbed diode laser pump power of 7.61 W, an average output power of 1.03 W was generated with a pulse duration of 335 ns and a repetition rate of 121 kHz, resulting in a pulse energy of 8.5 µJ.

High-intracavity-power thin-disk laser for the alignment of molecules.

We propose a novel approach for strong alignment of gas-phase molecules for experiments at arbitrary repetition rates. A high-intracavity-power continuous-wave laser will provide the necessary ac electric field of 10(10)-10(11) W/cm(2). We demonstrate thin-disk lasers based on Yb:YAG and Yb:Lu(2)O(3) in a linear high-finesse resonator providing intracavity power levels in excess of 100 kW at pump power levels on the order of 50 W. The multi-longitudinal-mode operation of this laser avoids spatial-hole burning even in a linear standing-wave resonator. The system will be scaled up as in-vacuum system to allow for the generation of fields of 10(11) W/cm(2). This system will be directly applicable for experiments at modern X-ray light sources, such as synchrotrons or free-electron lasers, which operate at various very high repetition rates. This would allow to record molecular movies through temporally resolved diffractive imaging of fixed-in-space molecules, as well as the spectroscopic investigation of combined X-ray-NIR strong-field effects of atomic and molecular systems.

Spectroscopy and laser operation of Sm(3+)-doped lithium lutetium tetrafluoride (LiLuF(4)) and strontium hexaaluminate (SrAl(12)O(19)).

We report on laser operation in the orange and red spectral range in samarium (Sm(3+))-doped fluoride and oxide crystals at 300 K. Sm(3+)-doped LiLuF(4) (LLF) and SrAl(12)O(19) (SRA) crystals were grown by the Czochralski-technique and utilized for spectroscopic investigations and laser experiments. The spin-forbidden transitions of Sm(3+)exhibit low cross sections the order of 10(-21) cm(2), but high radiative upper state lifetimes of several ms in both crystal systems. Under 2ω-OPSL-pumping at 480 nm, orange laser operation was achieved with Sm:LLF and Sm,Mg:SRA at lasing wavelengths of 606 nm and 593 nm, respectively. Furthermore laser oscillation was demonstrated at 648 nm in the red and 703 nm in the deep red spectral range with Sm:LLF and Sm,Mg:SRA, respectively. Output power levels of several 10 mW were obtained at slope efficiencies of up to 15 %. Most of the realized lasers were operating in a strongly modulated or even self-pulsing regime.

Q-switched operation of a femtosecond-laser-inscribed Yb:YAG channel waveguide laser using carbon nanotubes.

We demonstrate a diode-pumped femtosecond-laser-inscribed Yb:YAG channel waveguide laser, Q-switched by using single-walled carbon nanotubes (SWCNTs) near 1029 nm. We used saturable absorber mirrors (SAMs) fabricated by depositing SWCNTs on three different output couplers. Best performance of the 9.3-mm-long ultra-compact Q-switched waveguide laser is obtained with an output coupling transmission of 20%. In this case, a maximum average output power of 60 mW with a corresponding pulse energy of 37.7 nJ and a pulse duration of 88 ns at 1.59-MHz repetition rate were achieved. The highest pulse energy of 39.2 nJ and the shortest pulse duration of 78 ns were obtained with 30% and 10% output couplers, respectively.

Laser oscillation in Yb:YAG waveguide beam-splitters with variable splitting ratio.

In this Letter, we report on laser emission from Yb:YAG beam-splitters fabricated by direct femtosecond-laser inscription. These devices consist of two adjacent mirrored s-curved waveguides merged into a section allowing for multi-mode interference (MMI) and a straight waveguide. Nine-millimeter-long one-to-two beam-splitters with radii of curvature between 10 and 80 mm have been fabricated resulting in separations between the two arms of up to 0.65 mm. Due to the MMI-section, the splitting ratio was variable by slightly changing the incoupling conditions. Maximum laser output powers of 2.29 W and slope efficiencies of 52% were achieved with the best beam-splitter waveguide laser. For all radii of curvature exceeding 10 mm, similar efficiencies were demonstrated.

Growth and diode-pumped laser operation of Pr3+:ß-(Y0.5,Gd0.5)F3 at various transitions.

We report on the crystal growth of the orthorhombic low-temperature ß-phase of (Y0.5,Gd0.5)F3 (YGF) single crystals. The crystals were activated with trivalent praseodymium (Pr3+) and characterized with respect to their ground state absorption and stimulated emission properties. Under InGaN-laser-diode pumping, laser oscillation was obtained at more than ten wavelengths in the green, orange, red, and dark red spectral regions. In these initial experiments, output powers exceeding 100 mW and slope efficiencies between 10% and 30% were obtained. To the best of our knowledge, these results represent the first application of YGF crystals as laser host material for any active ion.

High-power red, orange, and green Pr³âº:LiYF4 lasers.

Laser experiments with Pr(3+):LiYF4 under excitation with a frequency doubled optically pumped semiconductor laser emitting 5 W at 479 nm were performed at seven different laser wavelengths of 523, 546, 604, 607, 640, 698, and 720 nm. At all these wavelengths the output power exceeded 1 W. The best performance at 523 nm with an output power of 2.9 W at a slope efficiency of 72% and an optical-to-optical efficiency of 67% with respect to the incident pump power represents the highest efficiency ever reported for a praseodymium-doped laser material.

Highly efficient continuous wave blue second-harmonic generation in fs-laser written periodically poled Rb:KTiOPO4 waveguides.

Waveguides were inscribed into a 9.5 mm long periodically poled KTiOPO4 crystal with a Ti:sapphire femtosecond-laser. Waveguiding was achieved between two parallel written tracks with spacings of 17-19 µm. The fundamental power of 1.6 W for frequency doubling in the waveguide was delivered by a continuous wave Ti:sapphire laser at a wavelength of 943.18 nm. A maximum output power of 76 mW in the blue spectral region was achieved. This corresponds to a single pass normalized conversion efficiency of 4.6% W(-1) cm(-2).

Thin-disk laser operation of Pr³âº,Mg²âº:SrAl12O19.

We present first results in applying the thin-disk concept to lasers directly emitting in the visible spectral range. The pump light was provided by 24 InGaN laser diodes emitting 1 W each at 444 nm, which were coupled into a 200 µm fiber. A 300 µm thin Pr3+,Mg2+:SrAl12O19 crystal served as gain medium. In continuous-wave operation an output power of 0.88 W and a slope efficiency of 12% with respect to the absorbed pump power were achieved at an emission wavelength of 643.5 nm. Modulating the pump source at a duty cycle of 10% yielded an instantaneous output power of 1.67 W, corresponding to a slope efficiency of 26%.

SESAM mode-locked red praseodymium laser.

We present the first semiconductor saturable absorber mirror (SESAM) mode-locked praseodymium solid-state laser. The laser is based on a Pr(3+):LiYF(4) crystal as gain medium and a GaInP-quantum well-based SESAM. Self-starting continuous-wave mode-locked laser operation with an average output power of 16 mW is achieved at a center wavelength of 639.5 nm. The laser operates at a repetition rate of ∼85.55 MHz and emits pulses with a duration of ∼18 ps.

Yellow laser performance of Dy³âº in co-doped Dy,Tb:LiLuF4.

We present laser results obtained from a Dy³âº-Tb³âº co-doped LiLuF4 crystal, pumped by a blue emitting InGaN laser diode, aiming for generation of a compact 578 nm source. We exploit the yellow Dy³âº transition 4F(9/2)⇒6H(13/2) to generate yellow laser emission. The lifetime of the lower laser level is quenched, via energy transfer, to co-doped Tb³âº ions in the fluoride crystal. We report the growth technique, spectroscopic study, and room temperature continuous wave laser results in a hemispherical cavity at 574 nm, and with a highly reflective output coupler at 578 nm. A yellow laser at 578 nm is very relevant for metrological applications, in particular for pumping of the forbidden ¹S0-³P0 ytterbium clock transition, which is recommended as a secondary representation of the second in the international system of units.

Holmium-doped Lu2O3, Y2O3, and Sc2O3 for lasers above 2.1 µm.

Efficient room-temperature laser operation was obtained in the wavelength range from 2117 nm to 2134 nm with Ho:Lu(2)O(3) and Ho:Y(2)O(3) as the active materials. With an FBG-stabilized Tm-doped fiber laser as the pump source, the maximum slope efficiency and output power of the Ho:Y(2)O(3) laser were 63% and 18.8 W, respectively. With Ho:Lu(2)O(3) the respective values were 76% and 25.2 W. With Ho:Sc(2)O(3) as the active material the accessible wavelength range could be expanded to 2158 nm in a diode-pumped setup.

Curved Yb:YAG waveguide lasers, fabricated by femtosecond laser inscription.

Straight and s-curve Yb(7%):YAG waveguides have been fabricated with the femtosecond laser writing technique. By employing a novel writing scheme an increase of the refractive index change could be achieved in comparison to waveguides written with the standard procedure. Straight waveguides, fabricated with this scheme, enabled highly efficient Ti:sapphire laser pumped waveguide lasers with slope efficiencies of 79% and output powers of more than 1 W. With slope efficiencies from 50% to 60% for the curved waveguide lasers with radii of curvature of R ≥ 20 mm the possibility of fs-laser written complex optical devices is demonstrated.

Wide wavelength tunability and green laser operation of diode-pumped Pr3+:KY3F10.

We report on wide spectral tunability of a quasi-continuous wave Pr(3+):KY(3)F(10) laser under InGaN laser diode excitation at 445 nm. The total tuning range exceeded 100 nm in the visible spectral range on several intervals between 521 nm and 737 nm. The broadest continuously tunable region of almost 50 nm extended from 688 nm to 737 nm. Furthermore we present what is to the best of our knowledge the first demonstration of continuous wave laser operation in Pr(3+):KY(3)F(10) on three transitions in the green spectral region. The highest output power of 121 mW was achieved at an emission wavelength of 554 nm with a slope efficiency of 27%.

Laser-written waveguides in KTP for broadband Type II second harmonic generation.

Femto-second laser writing was used to fabricate waveguides in a z-cut KTP sample with losses below 0.8 dB/cm. They were used for efficient, broad bandwidth, Type II birefringent second harmonic generation to the green. The temperature and wavelength bandwidth were, 28 C ∙ cm and 0.85 nm ∙ cm, respectively.

175 fs Tm:Lu2O3 laser at 2.07 µm mode-locked using single-walled carbon nanotubes.

Single-walled carbon nanotube saturable absorbers were designed and fabricated for passive mode-locking of bulk lasers operating in the 2 µm spectral range. Mode-locked lasers based on Tm:Lu2O3 single crystals containing different Tm3+-doping concentrations were studied. Nearly transform-limited pulses as short as 175 fs at 2070 nm were generated at 88 MHz repetition rate.

Continuous wave and mode-locked Yb3+:Y2O3 ceramic thin disk laser.

CW and mode-locked laser operation based on an Yb3+:Y2O3 ceramic thin disk is reported. In CW laser operation, an output power of 70 W with an optical-to-optical efficiency of 57.4% was achieved. A higher slope efficiency of 70% was also obtained with a 50-W pump laser diode with more suitable emission characteristics. In mode-locked laser operation, pulses as short as 547 fs with an average power of 7.4 W were obtained. To our knowledge, this is the first demonstration of a high power CW and mode-locked laser operation based on Yb3+:Y2O3 ceramic thin disks.