A method for measuring birefringence by use of thermal-light polarization-sensitive optical coherence tomography is presented. The use of thermal light brings to polarization-sensitive optical coherence tomography a resolution in the micrometer range in three dimensions. The instrument is based on a Linnik interference microscope and makes use of achromatic quarter-wave plates. A mathematical representation of the instrument is presented here, and the detection scheme is described, together with a discussion of the validity domain of the equations used to evaluate the birefringence in the presence of white-light illumination.

/pdf/full-field-birefringence-imaging-by-thermal-light-4ltdj6lvmi.pdf

Full-field birefringence imaging by thermal-light polarization-sensitive optical coherence tomography. I. Theory

We describe an instrument for measuring the magnitude of birefringence of tomographic images and the principal directions of axes that uses thermal-light polarization-sensitive optical coherence tomography. The instrument permits full-field measurements with an axial resolution of 1.5 μm and a transverse resolution limited by diffraction. We obtained a sensitivity of 84 dB, limited by shot noise, when we integrated the signal for 1 s. We verified the validity of the measurement by measuring the birefringence of a variable phase shifter. We present typical results obtained with optical samples.

/pdf/full-field-birefringence-imaging-by-thermal-light-8astlat2ly.pdf

Full-field birefringence imaging by thermal-light polarization-sensitive optical coherence tomography. II. Instrument and results

The effect of surface roughness onto the mirror scattering has been studied. Five kinds of substrates with different surface roughness were fabricated. On those substrates, dielectric multilayer coating for high reflectivity was deposited by ion-beam sputtering (IBS) and by electron-beam (EB) evaporation. Total integrated scattering (TIS) measurement setup was built for the evaluation of deposited samples. Most of the IBS mirrors showed lower scattering than the EB mirrors, which were deposited on the similar substrates in surface roughness. The ratio of substrate TIS to mirror TIS was defined for evaluation. It increased abruptly at approximately 2A in surface roughness, which indicated that to make low-loss mirrors, the substrate roughness should be less than 2A in rms.

Effects of substrate and deposition method onto the mirror scattering.

Absolute measurement is an effective way to obtain high-precision optical surface measurements. This paper describes a convenient absolute testing approach that allows reconstruction of surfaces using Zernike polynomials. This method requires a classical three-flat measurement and a one-rotation measurement before reconstructing the surface. Utilizing a well-established procedure, the absolute surface profile of the testing surface can be reconstructed with more Zernike orders than are provided by Fritz’s method. In particular, simulation of the testing error through recalculation of the test surface profile at a different angle could provide the optimized angle with a minimum testing error. This implies that an additional rotation measurement for the optimized angle can improve testing accuracy. The experimental results of a 100-mm flat surface provided a reflected root mean square (RMS) of 2.6 nm and a residual RMS of 0.1 nm.

Absolute optical flatness testing by surface shape reconstruction using Zernike polynomials

Mechanical stress in optical thin films can induce surface deflection of optical coatings. In the case of a substrate coated on both sides, a method is proposed which can provide perfect cancellation of this deflection, independently of the deposition process or any other external parameter, such as the temperature sensitivity of the mechanical stress. It is straightforward to implement this method, based on iso-admittance layers, since the thickness of such layers can be used to freely compensate for deflection effects only, without having any influence on the film's optical properties. This method is illustrated by two possible solutions for the design problem B from the Optical Interference Coatings (OIC) 2013 meeting.

Athermal compensation of the stress-induced surface deflection of optical coatings using iso-admittance layers.

Different approaches to improve the wavefront of low-loss mirrors used in the VIRGO gravitational wave antenna

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.

L. Dognin

Author Tools

Chat about Author

Papers

Different approaches to improve the wavefront of low-loss mirrors used in the VIRGO gravitational wave antenna