White light interferometer: applications in research and industry

Sujit Bandyopadhyay

doi:10.1117/12.2192151

15 June 2015 White light interferometer: applications in research and industry

Sujit Bandyopadhyay

Proceedings Volume 9654, International Conference on Optics and Photonics 2015; 965402 (2015) https://doi.org/10.1117/12.2192151
Event: International Conference on Optics and Photonics 2015, 2015, Kolkata, India

Abstract

Applications of interferometer are countless both in the research and commercial world. Laser sources offer precise measurements of relative path difference between two interfering beams. An exciting example is LIGO (laser Interferometer for Gravitational Observatory), which is aiming to resolve length change as small as 10^-19m over a 4 km length for detection of gravitational waves. However, laser is a disadvantage for microscopic imaging and surface topography applications usually required in semiconductor industry. A different approach for microscopy is to use white light in place of laser. White light due to its limited temporal coherence offers a multitude of benefits for imaging applications. An immediate benefit from white light is the sharp localisation of interference fringe that makes the 3D topography construction or OCT (Optical Coherence Topography) realisable using a Scanning White Light Interferometer (SWLI) imager. In Mirau Mode, SWLI performs high resolution imaging; whereas in Michelson mode Fourier Transform Spectroscopy (FTS) is realised. SWLI can easily be modified into PUPS (Pupil Plane SWLI) for Ellipsometry. Superimposing Michelson Interferometer known as VISAR (Velocity Interferometer System for Any reflector) can form interference fringes even in presence of wide angle light scattered from a moving illuminated object. This paper describes work undertaken at Nanometrics (UK) on simulation of SWLI fringes including high Numerical Aperture (NA) applications, thin film characterisation, OCT generation and Zemax modelling of compact dispersion-free vibration-immune Fourier-Transformed spectrometer. VISAR as a modified Mach-Zehnder Interferometer is also discussed based on the work at Rutherford-Appleton laboratory (UK).

Citation Download Citation

Sujit Bandyopadhyay "White light interferometer: applications in research and industry", Proc. SPIE 9654, International Conference on Optics and Photonics 2015, 965402 (15 June 2015); https://doi.org/10.1117/12.2192151

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
13 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Interferometers

Fourier transforms

Thin films

Mirrors

Objectives

Semiconducting wafers

Spatial frequencies

Show All Keywords

Keywords/Phrases

Search In:

Publication Years