Low-optical-loss, low-resistance Ag/Ge based ohmic contacts to n-type InP for membrane based waveguide devices

We present the development of Ag/Ge based ohmic contacts to n-type InP with both low contact resistances and relatively low optical losses. A specific contact resistance as low as 1.5×10-6 O cm2 is achieved by optimizing the Ge layer thickness and annealing conditions. The use of Ge instead of metal as the first deposited layer results in a low optical absorption loss in the telecommunication wavelength range. Compared to Au based contacts, the Ag based metallization also shows considerably reduced spiking effects after annealing. Contacts with different lengths are deposited on top of InP membrane waveguides to characterize the optical loss before and after annealing. A factor of 5 reduction of the propagation loss compared to the conventional Au/Ge/Ni contact is demonstrated. This allows for much more optimized designs for membrane photonic devices

Nanometallic lasers for optical interconnects

Abstract Semiconductor nanolasers with metallo-dielectric cavities are considered as promising light sources for optical interconnects. We review the first demonstrated devices of this type and outline our current research efforts on a waveguide-coupled nanolaser

Broadband operation of an InP optical phased array

We demonstrate the broadband operation and beam calibration over 70nm tuning range of an optical phased array (OPA) fabricated in a generic InP photonic integration platform, which enables multi-wavelength OPA operation. The broadband performance was demonstrated on an 8-channel OPA, whose calibration and phase modulator characterization were executed through near-field and far-field measurements. The architecture reported here is scalable, and the results are promising for reducing the complexity of calibration and control of large-scale OPAs for their use at multiple wavelengths, for example, for spectral imaging or 2D beam steering through dispersive gratings

Design of an efficient photonic crystal beam laser

Light sources on the micro and nano-scale are of great interest in recent years. Especially for data communication over centimeters densely integrated lasers are required. Ultra-small devices have been demonstrated[1]; the efficiency of such devices on the other hand is far behind values demonstrated for larger integrated laser concepts [2]. As a consequence the density of laser integration is currently limited by power consumption and cooling properties rather than the actual device footprint. In this work we present a design and first fabrication trials for a micron-scale laser promising record efficiencies exceeding 20%. A schematic representation of the laser is shown in figure 1 a)

Design of a waveguide-coupled nanolaser for photonic integration

Semiconductor nanolasers with metallo-dielectric cavities are considered as promising light sources for ultra-dense photonic integration. We present the design of a waveguide-coupled nanolaser based on optical and electrical simulations

Ohmic contacts with ultra-low optical loss on heavily doped n-type InGaAs and InGaAsP for InP-based photonic membranes

In this paper, we present significant reductions of optical losses and contact resistances in AgGe-based ohmic contacts to InP membranes. Due to the high solubility of Si in InGaAs and InGaAsP, heavily doped n-type contact layers are grown on InP wafers. This high doping concentration gives rise to annealing-free ohmic contacts and low contact resistances at the level of 10(-7) Omega cm(2). It also leads to strong band-filling effects in InGaAs and InGaAsP, which result in low optical absorption losses in the contact layer. Combined with the low optical loss of AgGe, a massive reduction of the propagation loss in membrane waveguides is observed compared with other existing solutions. An additional advantage is the minimal influence of thermal treatments during the processing, leading to very stable high-performing contacts

Waveguide-coupled nanopillar metal-cavity light-emitting diodes on silicon

Nanoscale light sources using metal cavities have been proposed to enable high integration density, efficient operation at low energy per bit and ultra-fast modulation, which would make them attractive for future low-power optical interconnects. For this application, such devices are required to be efficient, waveguide-coupled and integrated on a silicon substrate. We demonstrate a metal-cavity light-emitting diode coupled to a waveguide on silicon. The cavity consists of a metal-coated III-V semiconductor nanopillar which funnels a large fraction of spontaneous emission into the fundamental mode of an InP waveguide bonded to a silicon wafer showing full compatibility with membrane-on-Si photonic integration platforms. The device was characterized through a grating coupler and shows on-chip external quantum efficiency in the 10(-4)-10(-2) range at tens of microamp current injection levels, which greatly exceeds the performance of any waveguide-coupled nanoscale light source integrated on silicon in this current range. Furthermore, direct modulation experiments reveal sub-nanosecond electro-optical response with the potential for multi gigabit per second modulation speeds

VII Jornadas de Innovación Educativa de la Universidad de La Laguna: imaginar y comprender la innovación en la Universidad

The change of structure and process of the organizations of the current society has generated a great impact in the new way of working. Work teams coordination ensures that a team functions as a unitary whole; is identified as a key process to understand work team effectiveness. This paper presents a brief introduction of the recent research on Work teams in organizations and raises relevant issues about their implications for Pedagogy studies. This paper aims, first, to analyze the potential of team based organizations. And secondly, to examine the effects in pedagogy studies. Coordination is a process that involves the use of strategies and patterns of behavior aimed to integrate actions, knowledge and goals of interdependent members. The tasks have increased its difficulty, doing that individual resolution is very difficult or impossibleUniversidad de La Lagun