Title :
Waveguide-type acoustooptic frequency shifter with high diffraction efficiency driven by surface acoustic wave
Author :
Kakio, Shoji ; Kitamura, Michihide ; Nakagawa, Yasuhiko ; Hara, Takefumi ; Ito, Hiromasa ; Iizuka, Takashi ; Kobayashi, Tetsuya ; Watanabe, Masayuki
Author_Institution :
Interdisciplinary Graduate Sch. of Medicine & Eng., Yamanashi Univ., Kofu, Japan
Abstract :
The waveguide-type acoustooptic frequency shifter (AOFS) driven by a surface acoustic wave (SAW) in a tapered crossed-channel waveguide on a 128°-rotated Y-cut LiNbO3 substrate has been proposed for an optical wavelength of 1.55 μm. In this paper, to clarify the condition for the AOFS with a high diffraction efficiency, the SAW power required for 100% diffraction (P100) depending on the length of the AO interaction region and the driving frequency are investigated. First, the AOFS with the length of the AO interaction region of 3 mm was fabricated and the diffraction efficiency of 65% was obtained. Next, the measured values of P100 for the driving frequencies of 125 MHz and 200 MHz were found to be in agreement with the calculated P100. Furthermore, an optical frequency domain ranging using a frequency shifted-feedback fiber laser with the AOFS was demonstrated.
Keywords :
acousto-optical devices; fibre lasers; lithium compounds; surface acoustic wave waveguides; ultrasonic diffraction; 1.55 micron; 125 MHz; 200 MHz; AO interaction region; AOFS; LiNbO3; SAW; Y-cut LiNbO3 substrate; diffraction efficiency; driving frequency; frequency shifted-feedback fiber laser; optical frequency domain ranging; surface acoustic wave; tapered crossed-channel waveguide; waveguide-type acoustooptic frequency shifter; Acoustic diffraction; Acoustic waveguides; Acoustic waves; Fiber lasers; Frequency domain analysis; Frequency measurement; Optical diffraction; Optical surface waves; Optical waveguides; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 2004 IEEE
Print_ISBN :
0-7803-8412-1
DOI :
10.1109/ULTSYM.2004.1418295
