Research

Tailoring quantum structures for active photonic crystals

Abstract

This work is dedicated to the tailoring of quantum structures, with particular attention to the integration of selective area grown (SAG) active material into photonic crystal (PhC) slabs. The platform based on active PhC is vital to the realization of highly efficient elements with low energy consumption for on-chip and chip-to-chip optical communication. In order to develop metal-organic vapor phase epitaxial selective area etching and growth, a mask was fabricated in the HSQ e-beam resist including optimization of exposure and development conditions. By use of CBr4 as an etchant, in situ etching demonstrated various trench profiles along the [0-1-1] and [0-11] crystallographic directions. Selectively grown InGaAs/InP quantum wells (QWs) possessed distinct geometrical and optical properties in the cases of directly grown InGaAs and when an InP buffer was deposited underneath. The fabrication process for the incorporation of an SAG material into needle-shaped specimens for transmission electron microscopy or into PhCamplifiers was optimized to improve the alignment accuracy to below 100 nm. Micro-photoluminescence measurements of SAG QW showed a large wavelength red-shift (over 100 nm) compared to the unpatterned area and between the structures oriented along the [0-1-1] and [0-11] directions. Strong wavelength dependence with variations of the mask width of a few μm and opening sizes of hundreds of nanometers was observed. Incorporation of an active medium into PhC structures has showed promising results; in particular, the emission control of SAG QW matched the operating wavelength of photonic crystals. A strong photoluminescence signal in the slow light regime with the group index of 18 was demonstrated.

Info

Thesis PhD, 2015

UN SDG Classification
DK Main Research Area

    Science/Technology

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