P. Van Daele

A review on fabrication technologies for the monolithic integration of tapers with III-V semiconductor devices

The past few years a lot of effort has been put in the development and fabrication of III-V semiconductor waveguiding devices with monolithic integrated mode size converters (tapers). By integrating a taper with a waveguide device, the coupling losses and the packaging cost of OEICs in future fiber-optical networks can be much reduced. This paper gives an overview of different taper designs, the possible fabrication technologies and performances of tapered devices.

Recycling of guided mode light emission in planar microcavity light emitting diodes

Results are presented on planar microcavity light emitting diodes with different device diameters. A record external quantum efficiency of 20% is achieved for a 1.5 mm light emitting diode. The strong dependence of the quantum efficiency on current density and device size are compared with theoretical results. A good correspondence is obtained when spectral broadening and photon recycling are taken into account.

Atmospheric and low pressure shadow masked MOVPE growth of InGaAs(P)/InP and (In)GaAs/(Al)GaAs heterostructures and quantum wells

The shadow masked growth technique is presented as a tool to achieve thickness and bandgap variations laterally over the substrate during metalorganic vapor phase epitaxy. Lateral thickness and bandgap variations are very important for the fabrication of photonic integrated circuits, where several passive and active optical components need to be integrated on the same substrate. Several aspects of the shadow masked growth are characterized for InP based materials as well as for GaAs based materials. Thickness reductions are studied as a function of the mask dimensions, the reactor pressure, the orientation of the masked channels and the undercutting of the mask. The thickness reduction is strongly influenced by the mask dimensions and the reactor pressure, while the influence of the orientation of the channels and the amount of undercutting is only significant for narrow mask windows. During shadow masked growth, there are not only thickness variations but also compositional variations. Therefore, we studied the changes in In/Ga and As/P ratios for InGaAs and InGaAsP layers. It appears that mainly the In/Ga-ratio is responsible for compositional changes and that the As/P-ratio remains unchanged during shadow masked growth.

InAlGaP microcavity LEDs on Ge-substrates

We report on the growth of InAlGaP-layers and the fabrication of red microcavity LEDs (MCLEDs) on germanium (Ge) substrates. High-quality InAlGaP-layers have been grown on 3A Ge-substrates with excellent uniformity on photoluminescence wavelength and intensity. InAlGaP MCLEDs with an Al 0.55 Ga 0.45 As current spreading layer and 200 lm device diameter, emitting at 650 nm exhibit a maximum quantum e

Wavelength tuning by quantum well electrorefraction in a grating-assisted vertical coupler filter with InGaAsP/InAIGaAs MQW waveguide

ciency of 4.35% at 10 mA and a maximum optical power of 5 mW at 80 mA. MCLEDs emitting at 638 nm exhibit a maximum quantum e

Optical properties of a ZnSSe microcavity fabricated by epitaxial lift-off.

ciency of 4% at 10 mA and an optical power of 5 mW at 100 mA. GaP as an alternative current spreading layer is also investigated. ( 2000 Elsevier Science B.V. All rights reserved. PACS: 81.15.Gh; 85.60.J

Oxide-confined laser diodes with an integrated spot-size converter

We present the first demonstration ofE-field tuning of an InP-based grating-assisted vertical codirectional coupler filter with an InAIGaAs/InGaAsP MQW region in one of the waveguide cores. This filter exhibits 16 nm tuning by QW-electrorefraction, which is the highest value reported to our knowledge. The device has 3.2 nm bandwidth at 1568 nm for 1.6 mm interaction length, very low losses, good sidelobe suppression, high coupling efficiency and a modified polarization dependence.

MOVPE-based localized epitaxial growth techniques and its applications

Abstract We have fabricated and studied the optical properties of a planar II–VI ZnSSe microcavity. The MBE grown II–VI epi-layers were subsequently transplanted onto a metal coated GaAs substrate using the epitaxial lift-off technique. Comparison of the emission from the processed (microcavity) and unprocessed (non-microcavity) samples show evidence of spectral filtering and modified directionality which are due to the action of the cavity on the quantum well emission. Reflectance spectra confirm the Fabry-Perot resonance and excition feature are in the same spectral region. These results show that II–VI microcavities can be achieved using lift-off techniques.

Multi quantum well (MQW) lasers at 1550 nm fabricated with a single epitaxial selective growth step by MOVPE without waveguide etching

We report a new technique for the monolithic integration of a GaAs-based InGaAs-GaAs strained quantum-well laser and a spot-size converter (SSC) to improve the fiber coupling characteristics. The selective wet oxidation of AlGaAs is used to simplify the fabrication scheme of the component to a single planar epitaxial growth step and one conventional noncritical etch. This approach also allows us to avoid the photolithography of narrow features. An excellent reproducibility of the fabrication scheme was found. The integrated SSC exhibits very low transformation losses and a low beam divergence of 7.5/spl deg//spl times/13.5/spl deg/. The coupling efficiency to a 980-nm single-mode fiber is improved from -6.34 dB for a reference laser to -1.49 dB for the tapered device. The -1-dB alignment tolerance is /spl plusmn/1.5 /spl mu/m in the transverse direction and /spl plusmn/1.6 /spl mu/m in the lateral direction, respectively.

Monolithically integrated multi-wavelength laser by selective area growth with metal organic vapour phase epitaxy

As the functionality of InP-based photonic integrated circuits (PICs) is increasing rapidly and a wider range of components is integrated on a single chip, there is a need for advanced epitaxial techniques which enable the formation of regions with different bandgap energy simultaneously in a single epitaxial growth step. In this paper two MOVPE-based technologies which have the potential to meet those requirements are reviewed: selective area growth (SAG) and shadow masked growth (SMG).