Sensors 2010, 10(11), 9609-9619; doi:10.3390/s101109609
Article

A Comparison between Two Heterodyne Light Sources Using Different Electro-Optic Modulators for Optical Temperature Measurements at Visible Wavelengths

Department of Electro-Optical Engineering, Southern Taiwan University, 1, Nan-Tai St., Yung-Kang City, Tainan County 71005, Taiwan
* Author to whom correspondence should be addressed.
Received: 24 August 2010; in revised form: 24 September 2010 / Accepted: 13 October 2010 / Published: 29 October 2010
(This article belongs to the Section Physical Sensors)
PDF Full-text Download PDF Full-Text [511 KB, uploaded 29 October 2010 13:57 CEST]
Abstract: In this paper we have successfully demonstrated a z-propagating Zn-indiffused lithium niobate electro-optic modulator used for optical heterodyne interferometry. Compared to a commercial buck-type electro-optic modulator, the proposed waveguide-type modulator has a lower driving voltage and smaller phase variation while measuring visible wavelengths of 532 nm and 632.8 nm. We also demonstrate an optical temperature measurement system using a homemade modulator. The results show that the measurement sensitivities are almost the same values of 25 deg/°C for both the homemade and the buck-type modulators for a sensing light with a wavelength of 632.8 nm. Because photorefractive impacts are essential in the buck-type modulator at a wavelength of 532 nm, it is difficult to obtain reliable phase measurements, whereas the stable phase operation of the homemade one allows the measurement sensitivity to be improved up to 30 deg/°C with the best measurement resolution at about 0.07 °C for 532 nm.
Keywords: heterodyne interferometry; electro-optic modulator; optical temperature sensor

Article Statistics

Load and display the download statistics.

Citations to this Article

Cite This Article

MDPI and ACS Style

Twu, R.-C.; Lee, Y.-H.; Hou, H.-Y. A Comparison between Two Heterodyne Light Sources Using Different Electro-Optic Modulators for Optical Temperature Measurements at Visible Wavelengths. Sensors 2010, 10, 9609-9619.

AMA Style

Twu R-C, Lee Y-H, Hou H-Y. A Comparison between Two Heterodyne Light Sources Using Different Electro-Optic Modulators for Optical Temperature Measurements at Visible Wavelengths. Sensors. 2010; 10(11):9609-9619.

Chicago/Turabian Style

Twu, Ruey-Ching; Lee, Yi-Huan; Hou, Hong-Yao. 2010. "A Comparison between Two Heterodyne Light Sources Using Different Electro-Optic Modulators for Optical Temperature Measurements at Visible Wavelengths." Sensors 10, no. 11: 9609-9619.

Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert