We report a novel mode modulator based on a KTN crystal waveguide produced by femtosecond laser (fs-laser) writing. The KTN waveguide is a typical dual-line structure that depends on the decrease of refractive index at the focus area. The propagation loss of the waveguide along the TE polarization is as low as ~0.9 dB/cm at 632.8 nm. The investigation of confocal micro-Raman spectra reveals that the microstructure of the waveguide region has no obvious change during the femtosecond laser direct writing (FsLDW) procedure. Under the applied direct current (DC) electric field, the waveguide modes in the guiding structure can be modulated, resulting in mode conversion from TE00 to TE02. Both the experimental results and the theoretical simulation indicate that the mode modulation phenomenon originates from the space-charge-field induced refractive-index increment between the waveguide core and the bulk substrate. The simplicity and remarkable performance of the demonstrated device paves the way for integrating low-cost and high-efficient electric-optical modulator on photonics circuits.

A waveguide mode modulator based on femtosecond laser direct writing in KTN crystals

Atomic scale details of the formation of point defects and their evolution to phase transformation in silicon (Si) implanted β-Ga2O3 were studied using high resolution scanning transmission electron microscopy (STEM). The effect of Si implantation and the formation of defects was studied as a function of the dose of implanted atoms, and the detailed mechanism of lattice recovery was observed using both in situ and ex situ annealing of the implanted β-Ga2O3. The implantation created nanoscale dark spots in STEM images, which we identified as local γ-Ga2O3 inclusions generated by the relaxation of lattice due to ⟨010⟩ screw dislocations created by the implantation. The number and size of γ-Ga2O3 regions increased as the Si dose increased, and eventually the γ-Ga2O3 crystal phase (with stacking defects) took over the entire implanted volume when the peak Si concentration was over ∼1020 cm−3. Annealing above 1100 °C disintegrates the local γ-Ga2O3 phase and returns the structure to defect-free, single crystal β phase, likely indicating that point defects (such as Si interstitials and cation vacancies) are spatially redistributed by the annealing. However, when the structure is completely transformed to γ-Ga2O3 by the implantation, post-annealing leaves a high concentration of dislocations within the β phase, which relates to the inhomogeneous distribution of Si atoms detected by secondary ion mass spectrometry.

/pdf/atomic-scale-defect-formation-and-phase-transformation-in-si-150guc6x.pdf

Atomic scale defect formation and phase transformation in Si implanted β-Ga2O3

Optical planar and ridge waveguides in terbium scandium aluminum garnet crystal fabricated by ion implantation and precise diamond blade dicing

Two-dimensional (2D) materials are receiving significant attention for both fundamental research and industrial applications due to their unparalleled properties and wide application potential. In this case, the controllable modulation of their structures and properties is essential for the realization and further expansion of their applications. Accordingly, ion beam irradiation techniques, with large scope to adjust parameters, high manufacturing resolution, and a series of advanced equipment being developed, have been demonstrated to have obvious advantages in manipulating the structure and performance of 2D materials. In recent years, many research efforts have been devoted to uncovering the underlying mechanism and control rules regarding ion irradiation induced phenomena in 2D materials, aiming at fulfilling their application potential as soon as possible. Herein, we review the research progress in the interaction between energetic ions and 2D materials based on the energy transfer model, type of ion source, structural modulation, performance modification of 2D materials, and then their application status, aiming to provide useful information for researchers in this field and stimulating more research advances.

Recent progresses on ion beam irradiation induced structure and performance modulation of two-dimensional materials.

Concentric core-shell tracks and spectroscopic properties of SrTiO3 under intense electronic excitation

In this work, multiple-energy (400 keV, 450 keV, 500 keV) He ions implantation is proposed on Ytterbium doped YGG crystal. The choice of multiple-energy could widen the barrier layer by He ions accumulation at the end of the trajectory. Prism coupling and end-face coupling are used to obtain the optical properties in the waveguide region. The damage displacement profile and energy loss profile are simulated by SRIM 2010. The comparison between substrate and waveguide region on the micro-luminescence properties and Raman characteristics of Yb:YGG crystal are investigated also. The sequence annealing treatment results indicate that the sample surface break to pieces when the annealing temperature up to 600 °C, which provide direct evidence for the formation of He-bubble in He-implanted Yb:YGG crystal. Therefore, the results of this work provide reference value on YGG film fabrication by using multiple-energy He ion implantation.

Optical properties and surface blistering visualization on multiple-energy He-implanted Yb:YGG crystal by annealing treatment

Electronic energy loss and ion velocity correlation effects in track production in swift-ion-irradiated LiNbO3: A quantitative assessment between structural damage morphology and energy deposition

Natural MoS2 single crystals are irradiated with Ni ions with different fluences at 1 MeV and 357 MeV. The Stopping and Range of Ions in Matter software packages are used to simulate the process of Ni-ion beam peneration through the natural MoS2 single crystal. The electronic and nuclear stopping powers, displacement per atom and atoms vacancy profiles are simulated. The results show that S atoms are susceptible to the Ni-ion irradiation of natural MoS2 single crystals. Redshifts of the out-of-plane vibrations of S atoms and in-plane Mo–S phonon mode and the magnetic hysteresis loops are both recorded in the bulk and Ni-ion-irradiated natural MoS2 single crystals. 

Properties of the natural MoS2 crystal irradiated by medium- and high-energy Ni ions

In the present work, the evolution of atomic structures and related changes in energy state, atomic displacement and free volume of symmetrical grain boundaries (GB) under the effects of external strain in body-centered cubic (bcc) iron are investigated by the molecular dynamics (MD) method. The results indicate that without external strain, full MD relaxations at high temperatures are necessary to obtain the lower energy states of GBs, especially for GBs that have lost the symmetrical feature near GB planes following MD relaxations. Under external strain, two mechanisms are explored for the failure of these GBs, including slip system activation, dislocation nucleation and dislocation network formation induced directly by either the external strain field or by phase transformation from the initial bcc to fcc structure under the effects of external strain. Detailed analysis shows that the change in free volume is related to local structure changes in these two mechanisms, and can also lead to increases in local stress concentration. These findings provide a new explanation for the failure of GBs in BCC iron systems.

/pdf/evolution-of-symmetrical-grain-boundaries-under-external-9asl1jp5.pdf

Evolution of Symmetrical Grain Boundaries under External Strain in Iron Investigated by Molecular Dynamics Method

Study on the damage evolution of 6H-SiC under different phosphorus ion implantation conditions and annealing temperatures

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Yong Liu

Author Tools

Chat about Author