78 research outputs found
Coupling of single InGaAs quantum dots to the plasmon resonance of a metal nanocrystal
The authors report the coupling of single InGaAs quantum dots (QDs) to the surface plasmon resonance of a metal nanocrystal. Clear enhancement of the photoluminescence (PL) in the spectral region of the surface plasmon resonance is observed which splits up into distinct emission lines from single QDs in micro-PL. The hybrid metal-semiconductor structure is grown by molecular beam epitaxy on GaAs (100) utilizing the concept of self-organized anisotropic strain engineering for realizing ordered arrays with nanometer-scale precise positioning of the metal nanocrystals with respect to the QD
Laser emission and photodetection in an InP/InGaAsP layer integrated on and coupled to a Silicon-on-Insulator waveguide circuit
Laser emission from an InP/InGaAsP thin film epitaxial layer bonded to a Silicon-on-Insulator waveguide circuit was observed. Adhesive bonding using divinyl-tetramethyldisiloxane-benzocyclobutene (DVS-BCB) was used to integrate the InP/InGaAsP epitaxial layers onto the waveguide circuit. Light is coupled from the laser diode into an underlying waveguide using an adiabatic inverted taper approach. 0.9mW optical power was coupled into the SOI waveguide using a 500µm long laser. Besides for use as a laser diode, the same type of devices can be used as a photodetector. 50µm long devices obtained a responsivity of 0.23A/W
A model for luminescence of localized state ensemble
A distribution function for localized carriers,
, is proposed by solving a
rate equation, in which, electrical carriers' generation, thermal escape,
recapture and radiative recombination are taken into account. Based on this
distribution function, a model is developed for luminescence from localized
state ensemble with a Gaussian-type density of states. The model reproduces
quantitatively all the anomalous temperature behaviors of localized state
luminescence. It reduces to the well-known band-tail and luminescence quenching
models under certain approximations.Comment: 14 pages, 4 figure
Adhesive bonding of InP/InGaAsP dies to processed silicon-on-insulator wafers using DVS-bis-benzocyclobutene
The process of bonding InP/InGaAsP dies to a processed silicon-on-insulator wafer using sub-300 nm layers of DVS-bis-benzocyclobutene (BCB) was developed. The planarization properties of these DVS-bis-BCB layers were measured and an optimal prebonding die preparation and polymer precure are presented. Bonding quality and bonding strength are assessed, showing high-quality bonding with sufficient bonding strength to survive postbonding processing
Indium phosphide based membrane photodetector for optical interconnects on silicon
We have designed, fabricated and characterized an InP-based membrane photodetector on an SOI wafer containing a Si-wiring photonic circuit. New results on RF characterization up to 20 GHz are presented. The detector fabrication is compatible with wafer scale processing steps, guaranteeing compatibility towards future generation electronic IC processing
Integration of InP/InGaAsP photodetectors onto silicon-on-insulator waveguide circuits
The integration of optical functionalities on a chip has been a long standing goal in the optical community. Given the call for more integration, Silicon-on-Insulator (SOI) is a material system of great interest. Although mature CMOS technology can be used for the fabrication of passive optical functionality, particular photonic functions like efficient light emission still require III-V semiconductors. We present the technology for heterogeneous integration of III-V semiconductor optical components and SOI passive optical components using benzocyclobutene (BCB) die to wafer bonding. InP/InGaAsP photodetectors on SOI waveguide circuits were fabricated. The developed process is compatible with the fabrication of InP/InGaAsP light emitters on SOI
InP/InGaAs photodetector on SOI photonic circuitry
We present an InP-based membrane p-i-n photodetector on a silicon-on-insulator sample containing a Si-wiring photonic circuit that is suitable for use in optical interconnections on Si integrated circuits (ICs). The detector mesa footprint is 50 mu m(2), which is the smallest reported to date for this kind of device, and the junction capacitance is below 10 fF, which allows for high integration density and low dynamic power consumption. The measured detector responsivity and 3-dB bandwidth are 0.45 A/W and 33 GHz, respectively. The device fabrication is compatible with wafer-scale processing steps, guaranteeing compatibility toward future-generation electronic IC processing
Passively Mode-Locked 4.6 and 10.5 GHz Quantum Dot Laser Diodes Around 1.55 mu m With Large Operating Regime
tum dot laser diodes operating at wavelengths around 1.55 µm is reported. For a 4.6-GHz laser, a large operating regime of stable mode-locking, with RF-peak heights of over 40 dB, is found for injection currents of 750 mA up to 1.0 A and for values of the ab-sorber bias voltage of 0 V down to −3 V. Optical output spectra are broad, with a bandwidth of 6–7 nm. However, power exchange between different spectral components of the laser output leads to a relatively large phase jitter, resulting in a total timing jitter of around 35 ps. In a 4-mm-long, 10.5-GHz laser, it is shown that the operating regime of stable mode-locking is limited by the appear-ance of quantum dot excited state lasing, since higher injection current densities are necessary for these shorter lasers. The out-put pulses are stretched in time and heavily up-chirped with a value of 16–20 ps/nm. This mode of operation can be compared to Fourier domain mode-locking. The lasers have been realized using a fabrication technology that is compatible with further photonic integration. This makes such lasers promising candidates for, e.g., a coherent multiwavelength source in a complex photonic chip. Index Terms—Mode-locked lasers, quantum dots, semiconduc-tor lasers. I
Carrier capture and relaxation in Stranski-Krastanow InxGa1-xAs/GaAs(311)B quantum dots
We have investigated the structure and optical properties of In0.6Ga0.4As/GaAs(311)B quantum dots (QD's) formed by the Stranski-Krastanow growth mode during metal-organic chemical-vapor deposition. We find that (311)B QD structures display a higher energy QD luminescence emission and a stronger wetting-layer emission than (100) QD's of similar diameter and density. Temperature-dependent photoluminescence (PL) measurements reveal shallow QD confinement energies and strong interaction between neighboring quantum dots. Longer PL rise times of the ground-state emission of (311)B QD's compared to (100) QD's are ascribed to the effect of differing numbers, energies, and level spacings of QD confined states on intersublevel relaxation mechanisms at low-carrier excitation densities
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