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We have successfully fabricated and characterized room temperature continuous wave (cw) GaInAsSb/AlGaAsSb distributed feedback lasers emitting in the wavelength region between 2.499 and 2.573 μm. To the best of our knowledge, this is the longest emission wavelength realized with a GaSb-based DFB laser diode. The laser structure used for DFB processing was grown by solid source molecular beam epitaxy. A DFB concept requiring no subsequent overgrowth step was used by defining first-order Cr-Bragg gratings laterally patterned to a ridge waveguide. Threshold currents smaller than 60 mA and room temperature cw output powers up to 6.5 mW were obtained. The laser diodes show single mode emission with side mode suppression ratios (SMSR) of up to 32 dB.

We have investigated fabrication and characteristics of continuous wave (cw) GaInAsSb-AlGaAsSb distributed feedback (DFB) lasers in the 2.4-/spl mu/m range. Single-mode DFB emission is obtained without overgrowth by first order Cr-Bragg gratings on both sides of a laser ridge. The cw threshold currents for a cavity with a length of 800 /spl mu/m and a width of 4 /spl mu/m are around 30 mA. At 20/spl deg/C and at an injection current of 190 mA output powers of 8.5 mW were realized. Monomode emission with a side-mode suppression ratio (SMSR) of 33 dB has been obtained.

In this paper we demonstrate a tunable optically pumped semiconductor vertical external cavity surface emitting lasers (OPS-VECSELs) operating at around 2-mum wavelength range and emitting 1-W output power. Emission was obtained in a nearly diffraction-limited beam with a M2 value below 1.45

This study extends the lateral metal grating technology to the fabrication of GaInAsSb/AlGaAsSb single mode DFB lasers in the 2.4 /spl mu/ range. Laser characterization and measurements have been performed at 20/spl deg/C and 40/spl deg/C in order to show the constant temperature sensitivity over the whole grating range. The wide gain spectrum of the GaSb structures permits the realization of DFB lasers from 2.339 up to 2.392 /spl mu/m by variation of the grating periods from 326.88 nm to 334.88 nm.

Photoreflectance (PR) and photoluminescence (PL) have been applied to study the band structure and PL thermal quenching for Ga0.24In0.76Sb/GaSb quantum wells (QWs) of the widths varying from 10 to 21 nm. In the case of PR spectra, a strong GaSb-related resonance followed by Franz–Keldysh oscillations and PR resonances associated with optical transitions between the QW ground and the excited states have been clearly observed. The QW transitions have been identified on the basis of theoretical calculations which were performed in the framework of the effective mass model. Satisfactory agreement between theoretical calculations and experimental data has been found for the conduction band offset of ∼80%–85% that is consistent with the theoretical predictions, which were obtained within the “model-solid” theory. In the case of PL measurements, a very efficient QW emission without any localization features has been observed in the temperature range of 10–280 K. It has been concluded that the thermal quenching o...

We report on single-mode emitting coupled cavity ridge waveguide lasers on the GaSb material system in the 2 µm spectral range using two-dimensional (2D) photonic crystals (PhCs). Eight rows of 2D PhCs lateral to the ridge waveguides act as intermediate mirrors and are used to create two coupled cavities. This leads to preferential emission at one single longitudinal mode in the emission spectrum with side mode suppression ratios of 30-35 dB. Monolithic integration of high reflectivity 2D PhC back mirrors allows the realization of cavity lengths as short as 300 µm with threshold currents as low as 18.5 mA while reaching output powers well above 18 mW. Under variation of driving current the lasers exhibit both discrete and continuous tuning behavior over a wide current range very well explicable by simulation of the sub-threshold spectra, rendering the devices especially interesting for multi-gas sensing by absorption spectroscopy.

We report on room temperature continuous wave single mode GaInAsSb-GaSb quantum well lasers emitting beyond 3μm. Quantum well strain and composition were carefully adjusted to enhance the hole confinement without increasing electron confinement in order to avoid inhomogeneous quantum well pumping. In order to realize single mode emission as prerequisite for gas sensing applications, distributed feedback lasers were fabricated. A record single mode emission cw wavelength of 3019nm with a side mode suppression ratio of more than 30dB has been obtained. The room temperature peak power output per facet exceeds 3mW.

The optical transitions in Ga0.76In0.24As0.08Sb0.92∕GaSb quantum wells with the width varying from 10to21nm were studied by room temperature contactless electroreflectance (CER). In addition to the quantum well (QW) ground state transition (11H), the 22H and 33H transitions (where klH denotes transition between the kth heavy hole and the lth electron subbands) have been clearly observed in CER spectra. The experimental QW transition energies were compared with theoretical predictions based on an effective mass formalism model. It has been concluded that this QW is type I for both electron and holes and the conduction band offset for the unstrained Ga0.76In0.24As0.08Sb0.92∕GaSb interface equals ∼90%.

We present the realization of two-dimensional (2D) photonic crystals (PhCs) on the GaSb material system. An electron cyclotron resonance reactive ion etch process using Cl(2)/Ar allows the fabrication of PhCs covering air fill factors of f = 20%-50%, lattice periods of a = 400-500 nm and aspect ratios of 5:1. Quality and reflectivity of these structures are evaluated by incorporating the PhCs as high reflective back mirrors in GaSb-based ridge waveguide lasers with cavity lengths between 200 and 1100 µm with the front facet as cleaved. The shortest devices show remarkable threshold currents below 12 mA and efficiencies of 0.23 W A(-1), yielding a maximum output power of almost 19 mW, proving the applicability of the chosen approach to numerous further concepts based on 2D PhCs on the GaSb material system.

The authors present microlasers on the GaInSb∕AlGaAsSb material system. These microlasers are equipped with one dimensional or two dimensional photonic crystals (PhCs) acting as highly reflecting microscaled mirrors. Hence, microlasers with cavity lengths as short as 100μm could be realized, exhibiting output powers per facet of up to 6mW and side mode suppression ratios of 20dB in continuous wave operation.

We report the development of widely tunable lasers monolithically integrated with an internal photodiode separated from the active laser segments by one-dimensional photonic crystals (PhCs). The devices cover a large total wavelength span of 42?nm in single mode emission and are tunable in wavelength steps below 1?nm whereby the output power can simultaneously be controlled via the internal photodiode. Discrete wavelength tuning is obtained by small changes of the injection current using a two-coupled Fabry?Perot resonators configuration. The devices with single mode wavelength tunability and simultaneous power control on one single chip appear to be key enablers for future lab-on-a-chip applications in tunable diode laser spectroscopy.

For the first time, lasers with short period superlattice based quantum wells have successfully been fabricated and characterized on the (AlGaIn)(AsSb) material system. These new quantum wells are composed of alternating InSb/Ga(x)In(1-x)Sb layers with submonolayer thickness. Distributed-feedback lasers fabricated from the epitaxial layers emit in the wavelength range around 1.9 µm. Side mode suppression ratios over 35 dB and very low threshold currents of 23 mA were realized. The laser emission wavelength can be varied from 1.844 to 1.902 µm using grating periods between 255.0 and 263.8 nm.

A report is presented on the realisation of high brightness broad area lasers with emission wavelengths around 2 µm. A simple fabrication scheme based on a tilted contact geometry is demonstrated to be an easy and effective way to control the far-field characteristics of the presented laser devices. By varying the angle of the contact stripe against the laser facets normal the waveguiding properties of the gain guided cavities are externally controlled to achieve far-field angles as low as 2.1° at full width half maximum. This fact is ascribed to a systematic reduction of the number of oscillating lateral modes.

A 2 mum semiconductor disk laser with a tuning range of 35 nm and output power exceeding 500 mW is reported. The method for generating wavelength-tunable radiation is based on self-seeding the disk laser using optical feedback from a diffraction grating

Room-temperature continuous-wave operation of a singlemode GaInAsSb/GaSb/AlGaAsSb distributed feedback (DFB) laser is presented at a record long emission wavelength for this material system of 2.843 /spl mu/m. The threshold current at 20/spl deg/C is 75 mA. Mode selection was realised by metal gratings laterally patterned to a ridge waveguide. By varying the grating period, DFB emission from 2.738 up to 2.843 /spl mu/m is obtained.

We report a high-power optically pumped semiconductor vertical external cavity surface emitting laser operating at 2-mum wavelength. The gain material consisted of 15 GaInSb quantum-wells placed within a three-lambda GaSb cavity and grown on the top of an 18-pairs AlAsSb/GaSb Bragg reflector. For thermal management we have used a transparent diamond heat spreader bonded on the top of the structure. When cooled down to 5 degrees C, the laser emitted up to 1 W of optical power in a nearly diffraction-limited Gaussian beam demonstrating the high potential of antimonide material for VECSEL fabrication.

Molècules de senyalització extracel·lular; Mecanismes de la malaltia; Metàstasi Moléculas de señalización extracelular; Mecanismos de la enfermedad; Metástasis Extracellular signalling molecules, Mechanisms of disease; Metastasis Metastasis, the spread of malignant cells from a primary tumour to distant sites, causes 90% of cancer-related deaths. The integrin ITGB3 has been previously described to play an essential role in breast cancer metastasis, but the precise mechanisms remain undefined. We have now uncovered essential and thus far unknown roles of ITGB3 in vesicle uptake. The functional requirement for ITGB3 derives from its interactions with heparan sulfate proteoglycans (HSPGs) and the process of integrin endocytosis, allowing the capture of extracellular vesicles and their endocytosis-mediated internalization. Key for the function of ITGB3 is the interaction and activation of focal adhesion kinase (FAK), which is required for endocytosis of these vesicles. Thus, ITGB3 has a central role in intracellular communication via extracellular vesicles, proposed to be critical for cancer metastasis. The authors thank Hector Peinado and his laboratory team (Microenvironment & Metastasis Group, Molecular Oncology Program, Spanish National Cancer Research Centre (CNIO)). The authors thank Dr. Manel Bosch for helpful discussion and assistance with confocal microscopy. The authors thank Dr. Anne Spang and Dr Jordi Berenguer for helpful suggestions and discussion on the paper, and Jane Marshall for language review and editing support. This work was supported by Fondo de Investigaciones Sanitarias (PI14/01320), Redes Temáticas de Investigación Cooperativa en Salud (RD12/0036/0057) and CIBERONC (CB16/12/00363). SRC acknowledges support from the Generalitat de Catalunya (2014 SGR 1131). The CRG/UPF Proteomics Unit is part of the Spanish Infrastructure for Omics Technologies (ICTS OmicsTech) and it is a member of the ProteoRed PRB3 consortium which is supported by grant PT17/0019 of the PE I + D + i 2013-2016 from the Instituto de Salud Carlos III (ISCIII) and ERDF.