Absolute air refractive index measurement and tracking based on variable length vacuum cell

Xiangzhi Yu; Tieli Zhang; Jonathan D. Ellis

doi:10.1117/1.OE.55.6.064112

28 June 2016 Absolute air refractive index measurement and tracking based on variable length vacuum cell

Xiangzhi Yu, Tieli Zhang, Jonathan D. Ellis

Author Affiliations +

Optical Engineering, Vol. 55, Issue 6, 064112 (June 2016). https://doi.org/10.1117/1.OE.55.6.064112

Abstract

A refractometer system using four modified Wu-type heterodyne interferometers with a variable length vacuum cell is presented. The proposed system has two working modes: (1) a moving mode for measuring the absolute air refractive index at the start of a measurement and (2) a static mode for monitoring the air refractive index fluctuation with the same bandwidth as a traditional displacement interferometer. The system requires no gas filling or pumping during the measurement and can be used for real-time refractive index compensation. Comparison experiments with empirical equations are conducted to investigate the feasibility and performance of the proposed system. The standard deviation of the measurement difference between the proposed system and empirical equation is 2.8 parts in 10⁷, which is close to the uncertainty of our refractive index reference based on the accuracy of the environmental sensors. The relative refractive index tracking is a few parts in 10⁸ with a bandwidth of 10 Hz, but high bandwidths are readily achievable.

Citation Download Citation

Xiangzhi Yu, Tieli Zhang, and Jonathan D. Ellis "Absolute air refractive index measurement and tracking based on variable length vacuum cell," Optical Engineering 55(6), 064112 (28 June 2016). https://doi.org/10.1117/1.OE.55.6.064112

Published: 28 June 2016

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