The traditional annular electrode structure vertical cavity surface emitting semiconductor lasers (VCESL), the operating current injected into the active region is only in the very narrow channel of the annular edge of the area, make the distribution of the device internal thermal field uneven, affecting the output characteristic of the device. In this paper, present a new type of petaline electrode structure, form a number of independent emitting hole, making the device internal thermal field even, output characteristic of the device is improved remarkably. Active region is GaAs/Al 0.3 Ga 0.7 As three quantum well structure growing by molecular beam epitaxy (MBE), using the gradual change structure of AlGaAs as DBR. Prepare annular electrode and petaline electrode with the same process in the same epitaxial wafer. At the same time, analyzed internal thermal field distribution of this two kinds of different electrode structure by ANSYS finite element thermal analysis software. Through the analysis and calculation, we know, the Rthjc of new petaline electrode structure is 3.78°C/W, the Rthjc of traditional annular electrode structure is 4.78°C/W, thermal characteristic and stability of new petaline electrode structure are better than traditional annular electrode structure obviously.

Thermal characteristic analysis of new structure in 850nm VCSEL

With the rapid development of science and technology, the mid-wavelength Infrared imaging technology has been more and more widely used in military and industrial fields Mid-wavelength Infrared image is so blurring and noisy that it is difficult to obtain good detection and recognition results and the de-noising for mid-wavelength Infrared image is extremely important At present various de-noising methods have been applied and achieved partial results, but the methods all have their own limitations such that the high frequency signal is filtered and the edge of image is more obscure Unbiased estimation threshold wavelet is used to filter the mid-wavelength Infrared images with intellective predictive threshold and no need to build up the accurate estimation of noise deviation The simulation results show that this algorithm is superior to traditional filtering denoising methods and obtains high quality filtering images

The Study of Unbiased-estimation Threshold Wavelet De-noising Method Applied on Mid-wavelength Infrared Image

A new locally adaptive image denoising method, which exploits the intra-scale and inter-scale dependency in the dual-tree complex wavelet domain, is presented. Firstly, a recently emerged bivariate shrinkage rule is extended to a complex coefficient and its neighborhood, the corresponding nonlinear threshold functions are derived from the models using Bayesian estimation theory. Secondly, an adaptive weight, which is able to capture the inter-scale dependency of the complex wavelet coefficients, is combined to the obtained bishrink threshold. The experimental results demonstrate an improved denoising performance over related earlier techniques both in peak signal-to-noise ratio (PSNR) and visual effect.

Image denoising exploiting inter- and intra-scale dependency in complex wavelet domain

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.

Fengxia Yan

Author Tools

Chat about Author

Papers

Image denoising exploiting inter- and intra-scale dependency in complex wavelet domain