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Due to current crowding, the laser emission in medium size VCSELs starts at threshold in a linearly polarized ldquoflower moderdquo concentrated at the laser aperture periphery. Introducing a holding beam with orthogonal liner polarization we observe localized structure in the center of the device in the orthogonal polarization while the VCSEL keeps lasing in the same flower-mode. We support theoretically...
Vertical Cavity Surface Emitting Lasers (VCSELs) have many advantages but their multi-mode transverse mode behaviour introduces problems for applications where output mode shape is important such as injection into fibre. Several groups world-wide have been investigating introducing photonic-crystal-hole patterns into the top-DBR to control the transverse modes. This has been observed to enhance the...
VCSEL (Vertical-Cavity Surface-Emitting Laser) diodes are the youngest members of the semiconductor laser diode family. The main target of our work is focused on the modally characterization and the measurement of the basic properties (threshold current, spectral range of the laser emission, the current tunability) of the three VCSEL diode based on GaSb matrix, which are emitting in the infrared region...
In this work I present a new semi-vectorial model for analysis of photonic-crystal VCSELs (PC-VCSELs), which is a combination of the plane-wave expansion method with the effective index approximation. It allows to consider vectorial properties of electromagnetic field in three-dimensional structures while being still much more numerically efficient than fully-vectorial methods. I show the simulation...
We review recent results on wafer fused long wavelength VCSELs emitting in the 1310 - 2000 nm range. This technology allows reaching fundamental mode output in excess of 4.5 mW at room temperature and close to 3 mW at 70degC for both the 1310 nm and 1550 nm wavebands-the highest values obtained so far. Emission wavelength can be tuned continuously with current with a tuning range as large as 15 nm...
The versatile transceiver in study for the Super Large Hadron Collider (SLHC) will have to endure severe radiation and temperature conditions while providing a high speed digital communication link to cover the experiment requirements. For this, characterization and model analysis of the electro-optic components (in particular the semiconductor laser), is of utmost importance as it will enable the...
The MQW GaInAsSb/AlGaAsSb lasers are monomodal throughout almost the whole temperature range of its operation, and they can be tuned in a wide spectral range. With the combination of the Fourier transform spectrometer and the diode lasers as sources of coherent radiation, we compared the spectra measured with a FTIR spectrometer in its absorption arrangement using a 50 W halogen lamp, with a laser...
This paper investigates experimentally the suitability of low-cost vertical cavity surface emitting lasers (VCSEL) for radio-over-fibre transmission of UMTS signals. Three directly-modulated VCSEL configurations are investigated: Multi-mode VCSELs operating at 850 nm and 1300 nm respectively in multi-mode fibres (MMF), and single-mode VCSELs operating at 1310 nm with standard single-mode fibre (SSMF)...
We fabricated and characterized a vertical-cavity surface-emitting laser (VCSEL) based on (110) InGaAs/GaAs multiple quantum wells (MQWs). Circularly polarized lasing in the (110) VCSEL by optical injection of spin-polarized electrons has been demonstrated at 77 K and room temperature. A high degree of circular polarization, 0.94, was observed at 77 K, reflecting the long electron spin relaxation...
A new vertical-cavity surface-emitting laser structure employing a dielectric photonic crystal mirror has been suggested and been numerically investigated. The new structure has a smaller threshold gain, a moderate strength of single-transverse-mode operation, a high quality of emission beam free from the scattering, and a potential of considerably increasing the single-mode output power.
We demonstrate first experimental evidence of polarization switching in Stranski-Krastanov (SK) and submonolayer (SML) quantum dot (QD) vertical-cavity surface-emitting lasers (VCSELs). In the case of a SMLQD VCSEL polarization switching is accompanied by polarization mode hopping and is associated with a change of linearly polarized light to elliptically polarized one, hence switching takes place...
Three methods to obtain in GaAs-based oxide-confined GaInNAs/GaAs quantum-well (QW) VCSELs an efficient emission of the 1.3-mum radiation have been analysed and compared with the aid of the comprehensive fully self-consistent model. In the tuned VCSEL, QW composition (high N content) and thickness are selected to tune the 1.3-mum emission which ensures low threshold currents. However, manufacturing...
In the present paper, the comprehensive self-consistent VCSEL physical model is used to analyse excitation of successive transverse cavity modes in oxide-confined (OC) vertical-cavity surface-emitting diode lasers (VCSELs) using the double intra-cavity-contacted 5-lambda-cavity double-quantum-well GaAs-based GaInNAs/GaAs OC VCSEL emitting the 1.3-mum radiation as a typical VCSEL example. As expected,...
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