48 research outputs found
Comparison of processing-induced deformations of InP bonded to Si determined by e-beam metrology: direct vs. adhesive bonding
In this paper, we employ an electron beam writer as metrology tool to
investigate distortion of an exposed pattern of alignment marks in
heterogeneously bonded InP on silicon. After experimental study of three
different bonding and processing configurations which represent typical on-chip
photonic device fabrication conditions, the smallest degree of
linearly-corrected distortion errors is obtained for the directly bonded wafer,
with the alignment marks both formed and measured on the same InP layer side
after bonding (equivalent to single-sided processing of the bonded layer).
Under these conditions, multilayer exposure alignment accuracy is limited by
the InP layer deformation after the initial pattern exposure mainly due to the
mechanical wafer clamping in the e-beam cassette. Bonding-induced InP layer
deformations dominate in cases of direct and BCB bonding when the alignment
marks are formed on one InP wafer side, and measured after bonding and
substrate removal from another (equivalent to double-sided processing of the
bonded layer). The findings of this paper provide valuable insight into the
origin of the multilayer exposure misalignment errors for the bonded III-V on
Si wafers, and identify important measures that need to be taken to optimize
the fabrication procedures for demonstration of efficient and high-performance
on-chip photonic integrated devices.Comment: 7 pages, 6 figure
Experimental Demonstration of Nanolaser with sub-A Threshold Current
We demonstrate a photonic crystal nanolaser exhibiting an ultra-low threshold
of 730 nA at telecom wavelengths. The laser can be directly modulated at 3 GHz
at an energy cost of 1 fJ/bit. This is the lowest threshold reported for any
laser operating at room temperature and facilitates low-energy on-chip links.Comment: 3 pages with 2 figure
Fine-tunable near-critical Stranski-Krastanov growth of InAs/InP quantum dots
Emerging applications of self-assembled semiconductor quantum dot (QD)-based
nonclassical light sources emitting in the telecom C-band (1530 to 1565 nm)
present challenges in terms of controlled synthesis of their low-density
ensembles, critical for device processing with an isolated QD. This work shows
how to control the surface density and size of InAs/InP quantum dots over a
wide range by tailoring the conditions of Stranski-Krastanow growth. We
demonstrate that in the near-critical growth regime, the density of quantum
dots can be tuned between and . Furthermore, employing
both experimental and modeling approaches, we show that the size (and therefore
the emission wavelength) of InAs nanoislands on InP can be controlled
independently from their surface density. Finally, we demonstrate that our
growth method gives low-density ensembles resulting in well-isolated
QD-originated emission lines in the telecom C-band
Photonic crystal Fano resonances for realizing optical switches, lasers and non-reciprocal elements
Quantifying non-uniform InP-on-Si wafer expansion with a sub-50 nm precision using E-beam metrology
Investigation of the Expansion in InP layer bonded to Si and its Effects on the Performance of the Photonic Crystal Lasers with the Buried Heterostructure
Scalable quantum photonic devices emitting indistinguishable photons in the telecom C-band
Epitaxial semiconductor quantum dots (QDs) are a promising resource for
quantum light generation and the realization of non-linear quantum photonic
elements operating at the single-photon level. Their random spatial
distribution resulting from their self-organized nature, however, restrains the
fabrication yield of quantum devices with the desired functionality. As a
solution, the QDs can be imaged and localized, enabling deterministic device
fabrication. Due to the significant electronic noise of camera sensors
operating in the telecommunication C-band, , this
technique remained challenging. In this work, we report on the imaging of QDs
epitaxially grown on InP with emission wavelengths in the telecom C-band
demonstrating a localization accuracy of . This is enabled by
the hybrid integration of QDs in a planar sample geometry with a bottom
metallic reflector to enhance the out-of-plane emission. To exemplify our
approach, we successfully fabricate circular Bragg grating cavities around
single pre-selected QDs with an overall cavity placement uncertainty of
. QD-cavity coupling is demonstrated by a Purcell enhancement
up to with an estimated photon extraction efficiency of
into a numerical aperture of . We demonstrate triggered
single-photon emission with and
record-high photon indistinguishability associated with two-photon interference
visibilities of and without and with temporal postselection, respectively.
While the performance of our devices readily enables proof-of-principle
experiments in quantum information, further improvements in the yield and
coherence may enable the realization of non-linear devices at the single photon
level and advanced quantum networks at the telecom wavelength.Comment: 9 pages, 4 figures, Supplemental Material: 20 pages, 18 figure