Far-field characterization of the thermal dynamics in lasing microspheres

This work reports the dynamical thermal behavior of lasing microspheres placed on a dielectric substrate while they are homogeneously heated-up by the top-pump laser used to excite the active medium. The lasing modes are collected in the far-field and their temporal spectral traces show characteristic lifetimes of about 2 ms. The latter values scale with the microsphere radius and are independent of the pump power in the studied range. Finite-Element Method simulations reproduce the experimental results, revealing that thermal dynamics is dominated by heat dissipated towards the substrate through the medium surrounding the contact point. The characteristic system scale regarding thermal transport is of few hundreds of nanometers, thus enabling an effective toy model for investigating heat conduction in non-continuum gaseous media and near-field radiative energy transfer

On-chip lateral Si:Te PIN photodiodes for room-temperature detection in the telecom optical wavelength bands

Photonic integrated circuits require photodetectors that operate at room temperature with sensitivity at telecom wavelengths and are suitable for integration with planar complementary-metal-oxide-semiconductor (CMOS) technology. Silicon hyperdoped with deep-level impurities is a promising material for silicon infrared detectors because of its strong room-temperature photoresponse in the short-wavelength infrared region caused by the creation of an impurity band within the silicon band gap. In this work, we present the first experimental demonstration of lateral Te-hyperdoped Si PIN photodetectors operating at room temperature in the optical telecom bands. We provide a detailed description of the fabrication process, working principle, and performance of the photodiodes, including their key figure of merits. Our results are promising for the integration of active and passive photonic elements on a single Si chip, leveraging the advantages of planar CMOS technology.Comment: 18 pages, 5 Figures, Supplementary informatio

Wafer-scale nanofabrication of telecom single-photon emitters in silicon

A highly promising route to scale millions of qubits is to use quantum photonic integrated circuits (PICs), where deterministic photon sources, reconfigurable optical elements, and single-photon detectors are monolithically integrated on the same silicon chip. The isolation of single-photon emitters, such as the G centers and W centers, in the optical telecommunication O-band, has recently been realized in silicon. In all previous cases, however, single-photon emitters were created uncontrollably in random locations, preventing their scalability. Here, we report the controllable fabrication of single G and W centers in silicon wafers using focused ion beams (FIB) with high probability. We also implement a scalable, broad-beam implantation protocol compatible with the complementary-metal-oxide-semiconductor (CMOS) technology to fabricate single telecom emitters at desired positions on the nanoscale. Our findings unlock a clear and easily exploitable pathway for industrial-scale photonic quantum processors with technology nodes below 100 nm

Blue-green to near-IR switching electroluminescence from Si-rich silicon oxide/nitride bilayer structures

Blue green to near-IR switching electroluminescence (EL) has been achieved in a metal-oxide-semiconductor light emitting device, where the dielectric has been replaced by a Si-rich silicon oxide/nitride bilayer structure. To form Si nanostructures, the layers were implanted with Si ions at high energy, resulting in a Si excess of 19%, and subsequently annealed at 1000 °C. Transmission electron microscopy and EL studies allowed ascribing the blue-green emission to the Si nitride related defects and the near-IR band with the emission of the Si-nanoclusters embedded into the SiO2 layer. Charge transport analysis is reported and allows for identifying the origin of this twowavelength switching effect

Mid- and far-infrared localized surface plasmon resonances in chalcogen-hyperdoped silicon

Plasmonic sensing in the infrared region employs the direct interaction of the vibrational fingerprints of molecules with the plasmonic resonances, creating surface-enhanced sensing platforms that are superior than the traditional spectroscopy. However, the standard noble metals used for plasmonic resonances suffer from high radiative losses as well as fabrication challenges, such as tuning the spectral resonance positions into mid- to far-infrared regions, and the compatibility issue with the existing complementary metal-oxide-semiconductor (CMOS) manufacturing platform. Here, we demonstrate the occurrence of mid-infrared localized surface plasmon resonances (LSPR) in thin Si films hyperdoped with the known deep-level impurity tellurium. We show that the mid-infrared LSPR can be further enhanced and spectrally extended to the far-infrared range by fabricating two-dimensional arrays of micrometer-sized antennas in a Te-hyperdoped Si chip. Since Te-hyperdoped Si can also work as an infrared photodetector, we believe that our results will unlock the route toward the direct integration of plasmonic sensors with the one-chip CMOS platform, greatly advancing the possibility of mass manufacturing of high-performance plasmonic sensing systems.Comment: 20 pages, 5 figure

Erbium emission in MOS light emitting devices: from energy transfer to direct impact excitation

The electroluminescence (EL) at 1.54 µm of metal-oxide-semiconductor (MOS) devices with Er3+ ions embedded in the silicon-rich silicon oxide (SRSO) layer has been investigated under different polarization conditions and compared with that of erbium doped SiO2 layers. EL time-resolved measurements allowed us to distinguish between two different excitation mechanisms responsible for the Er3+ emission under an alternate pulsed voltage signal (APV). Energy transfer from silicon nanoclusters (Si-ncs) to Er3+ is clearly observed at low-field APV excitation. We demonstrate that sequential electron and hole injection at the edges of the pulses creates excited states in Si-ncs which upon recombination transfer their energy to Er3+ ions. On the contrary, direct impact excitation of Er3+ by hot injected carriers starts at the Fowler-Nordheim injection threshold (above 5 MV cm−1) and dominates for high-field APV excitation

Rare earth- and Si nanostructure-based light emitting devices for integrated photonics

[spa] Esta tesis presenta un trabajo experimental en el desarrollo de iones de tierras raras y nanoestructuras de Si como plataforma de materiales para dispositivos de emisión de luz (LEDs) en el rango visible e infrarrojo cercano. Se han fabricado diferentes dispositivos electroluminiscentes basados en capas simples, dobles o triples de óxido de silicio y/o nitruro de silicio dopados o no con tierras raras. Para ello se han empleado varias técnicas de fabricación compatibles con la tecnología CMOS; a saber, depósito de vapor químico asistido por plasma (PECVD), pulverización catódica mediante magnetrón, depósito de vapor químico a baja presión (LPCVD) e implantación de iones. Así mismo, las propiedades estructurales y de composición de las capas fabricadas han sido determinadas mediante el uso de técnicas de caracterización tales como TOF-SIMS, SIMS, XPS, EFTEM, FIB y elipsometría. Además, a temperatura ambiente y altas temperaturas (25 0C – 300 0C) se han estudiado las propiedades electro-ópticas en los regímenes cuasi-estático y dinámico. Por lo general, las técnicas electro-ópticas empleadas fueron corriente-voltaje, capacitancia-voltaje, estudio de carga hasta la ruptura, electroluminiscencia (EL)-corriente, EL-voltaje y EL resuelta en tiempo.[eng] This thesis presents experimental work on developing rare-earth ions and Si nanostructures as a material platform for light emitting devices (LEDs) in the visible and near-infrared range. The realization of the different electroluminescent devices, based on a single, bi- or tri-layer approach of silicon oxide and/or silicon nitride co-doped or not with rare earth ions, is successfully performed. Several complementary metal-oxide-semiconductor (CMOS) compatible fabrication techniques such as co-magnetron sputtering, plasma-enhanced chemical vapor deposition (PECVD), low-pressure chemical vapor deposition (LPCVD) and ion implantation are used. By using characterization techniques such as time of flight secondary ion mass spectrometry (TOF-SIMS), secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS), energy-filtered transmission electron microscopy (EFTEM), focused ion beam (FIB) and ellipsometry, the structural and compositional properties of the studied active layers are determined. In addition, electro-optical properties at room and at high temperatures (25 0C – 300 0C) under quasi-static and dynamic regimes are studied in both visible and near-infrared spectral region. Typically, the used electro-optical techniques have been current-voltage, capacitance-voltage, charge to breakdown, electroluminescence (EL)-current, EL-voltage and time-resolved EL

Copropagating pump and probe experiments on Si-nc in SiO2 rib waveguides doped with Er: The optical role of non-emitting ions

We present a study that demonstrates the limits for achieving net optical gain in an optimized waveguide where Si nanoclusters in SiO2 codoped with Er3+ are the active material. By cross correlating absorption losses measurements with copropagant pump (λpump = 1.48 µm) and probe (λprobe = 1.54 µm) experiments we reveal that the role of more than 80% of the total Er3+ population present on the material (intended for optical amplification purposes) is to absorb the propagating light, since it is unfeasible to invert it