Investigation of Ge Substrate Thicknesses and Epitaxy Growth Conditions on Optical and Material Properties of Ge-based VCSELs
Journal
Photonics North, PN
Journal Issue
2025
Start Page
1
End Page
2
ISSN
26938324
ISBN (of the container)
979-833155623-5
ISBN
[9798331556235]
Date Issued
2025-05-20
Author(s)
Abstract
We present a comparative study of the optical and material property dependences of VCSELs on Ge or GaAs substrate thicknesses and epitaxy process conditions. It was found that adjusting the Ge substrate thickness and optimizing the epitaxy process can shift the stopband center and cavity resonance wavelength by several nanometers. Ge-based VCSELs exhibit improved epitaxial uniformity, smaller deviations from design specifications, reduced stoichiometry variations, and strain magnitudes comparable to those of GaAs-based counterparts. In the selected 46.92 μ m2 sample area, no defects were observed in the quantum well (QW) regions of Ge-based VCSELs, and the threading dislocation density (TDD) was measured to be below 2.13 × 106 cm-2. These results highlight the potential of Ge substrates as promising candidates for advanced VCSELs.
Event(s)
2025 Photonics North, PN 2025
Subjects
epitaxy growth
Ge-based substrates
quantum well
thickness control
transmission electron microscopy
VCSEL
SDGs
Publisher
Institute of Electrical and Electronics Engineers Inc.
Type
conference paper