Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

High-precision diode-laser-based temperature measurement for air refractive index compensation

Not Accessible

Your library or personal account may give you access

Abstract

We present a laser-based system to measure the refractive index of air over a long path length. In optical distance measurements, it is essential to know the refractive index of air with high accuracy. Commonly, the refractive index of air is calculated from the properties of the ambient air using either Ciddor or Edlén equations, where the dominant uncertainty component is in most cases the air temperature. The method developed in this work utilizes direct absorption spectroscopy of oxygen to measure the average temperature of air and of water vapor to measure relative humidity. The method allows measurement of temperature and humidity over the same beam path as in optical distance measurement, providing spatially well-matching data. Indoor and outdoor measurements demonstrate the effectiveness of the method. In particular, we demonstrate an effective compensation of the refractive index of air in an interferometric length measurement at a time-variant and spatially nonhomogeneous temperature over a long time period. Further, we were able to demonstrate 7mK RMS noise over a 67m path length using a 120s sample time. To our knowledge, this is the best temperature precision reported for a spectroscopic temperature measurement.

© 2011 Optical Society of America

Full Article  |  PDF Article
More Like This
Spectroscopic thermometry for long-distance surveying

Teemu Tomberg, Thomas Fordell, Jorma Jokela, Mikko Merimaa, and Tuomas Hieta
Appl. Opt. 56(2) 239-246 (2017)

Real-time compensation of the refractive index of air in distance measurement

Hyun Jay Kang, Byung Jae Chun, Yoon-Soo Jang, Young-Jin Kim, and Seung-Woo Kim
Opt. Express 23(20) 26377-26385 (2015)

Air refractive index measurement using low-coherence interferometry

Tomáš Pikálek and Zdeněk Buchta
Appl. Opt. 54(16) 5024-5030 (2015)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (6)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Tables (3)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (6)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved