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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 23 — Nov. 5, 2012
  • pp: 25990–25999

Simple and cost-effective thickness measurement terahertz system based on a compact 1.55 μm λ/4 phase-shifted dual-mode laser

Han-Cheol Ryu, Namje Kim, Sang-Pil Han, Hyunsung Ko, Jeong-Woo Park, Kiwon Moon, and Kyung Hyun Park  »View Author Affiliations

Optics Express, Vol. 20, Issue 23, pp. 25990-25999 (2012)

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A simple thickness measurement method based on the coherent homodyne CW THz system was demonstrated; it does not require precise control of the frequencies of the beat source, and only accurate scanning of the optical delay line is needed. Three beat frequencies are sufficient for measuring the thickness of a sample without considering the modulo 2π ambiguity. A novel compact 1.55 μm λ/4 phase-shifted dual-mode laser (DML) was developed as an optical beat source for the CW THz system. The thickness of a sample was accurately estimated from the measurements using the proposed method. Our results clearly show the possibility of a compact, simple, and cost-effective CW THz system for practical applications.

© 2012 OSA

OCIS Codes
(140.3600) Lasers and laser optics : Lasers, tunable
(140.5960) Lasers and laser optics : Semiconductor lasers
(300.6495) Spectroscopy : Spectroscopy, teraherz

ToC Category:
Instrumentation, Measurement, and Metrology

Original Manuscript: August 30, 2012
Revised Manuscript: October 26, 2012
Manuscript Accepted: October 26, 2012
Published: November 2, 2012

Han-Cheol Ryu, Namje Kim, Sang-Pil Han, Hyunsung Ko, Jeong-Woo Park, Kiwon Moon, and Kyung Hyun Park, "Simple and cost-effective thickness measurement terahertz system based on a compact 1.55 μm λ/4 phase-shifted dual-mode laser," Opt. Express 20, 25990-25999 (2012)

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