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Bench Testing of New Polarimeter with Silicon Photoelastic Modulator for Short Wavelength FIR Laser

Tsuyoshi AKIYAMA, Kazuo KAWAHATA, Shigeki OKAJIMA¹⁾, Kazuya NAKAYAMA¹⁾ and Theodore C. OAKBERG²⁾

National Institute for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292, Japan

1)

Chubu University, 1200 Matsumoto-cho, Kasugai-shi, Aichi 487-8501, Japan

2)

Hinds Instruments, Inc., 3175 NW Aloclek Drive Hillsboro, Oregon 97124, U.S.A.

(Received 12 December 2006 / Accepted 11 April 2007 / Published 20 November 2007)

Abstract

A short wavelength laser whose wavelength is about 50 μm is preferable for a polarimeter and an interferometer in large fusion devises. This paper reports the development of a polarimeter with a photoelastic modulator (PEM) for a CH₃OD laser (wavelengths of 57.2 and 47.6 μm). The PEM with a high-resistive silicon as a photoelastic element has been newly developed. The transmissivity of the high-resistive silicon is high in a far infrared region. The polarimeter with the Si PEM has been tested and the polarization angle is successfully measured. Noise sources (a multi-reflection of the laser beam in the photoelastic element, a measurement error of amplitude of a detector output and an estimation error of the retardation) of the measured angle are also discussed.

Copyright (c) 2007 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

polarimeter, CH₃OD laser, photoelastic modulator, high-resistive silicon, AR coating

DOI: 10.1585/pfr.2.S1113

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References

• [1] S. Ide, J. Plasma Fusion Research SERIES, 4, 99 (2001).
• [2] T. Shimozuma et al., Nucl. Fusion 45, 1396 (2005).
• [3] H. Soltwisch, Plasma Phys. Contr. Fusion 34, 1669 (1992).
• [4] A.J.H. Donné et al., Rev. Sci. Instrum. 75, 4694 (2004).
• [5] H. Soltwisch, Rev. Sci. Instrum. 57, 1939 (1986).
• [6] J.H. Rommers, J. Howard, Plasma Phys. Control. Fusion 38, 1805 (1996).
• [7] L. Guidicottie et al., Plasma Phys. Control. Fusion 46, 681 (2004).
• [8] S. Okajima et al., Rev. Sci. Instrum 72, 1094 (2001).
• [9] K. Nakayama et al., Rev. Sci. Instrum 75, 329 (2004).
• [10] K. Kawahata et al., Rev. Sci. Instrum 75, 3508 (2004).
• [11] K. Kawahata et al., Rev. Sci. Instrum 77, 10F132-1 (2006).
• [12] Y. Kawano et al., Rev. Sci. Instrum 72, 1068 (2001).
• [13] S.E. Segre, Plasma Phys. Controlled Fusion 41, R57 (1999).
• [14] T.C. Oakberg, Opt. Eng. 34, 1545 (1995).
• [15] A.J. Gatesman et al., IEEE Microwave and Guided Wave Letters 10, (2006).
• [16] I. Hosako, Journal of the National Institute of Information and Communications Technology 51, 1/2 (2004).

This paper may be cited as follows:

Tsuyoshi AKIYAMA, Kazuo KAWAHATA, Shigeki OKAJIMA, Kazuya NAKAYAMA and Theodore C. OAKBERG, Plasma Fusion Res. 2, S1113 (2007).