The second harmonic light of an 842 nm diode laser was generated from a KNbO3 crystal in an external ring resonator. The power of the second harmonic light was about 0.8 mV at an input fundamental power of 87 mW. The laser frequency was stabilized to the resonance frequency of the ring resonator, and the frequency fluctuation was measured as about 3 MHz.

1. L. A. Glasser, IEEE J. Quant. Electr. QE-16, 525(1980)
   
2. B. Dahmani, L. Hollberg, and R. Drullinger, Opt. Lett. 12, 876 (1987)
   
3. H. S. Lee, S. H. Yang, Y. B. Kim, S. E. Park, H. Cho, and J. D. Park, Jpn. J. Appl. Phys. Part I, 35, 276 (1996)
   
4. P. Gunter, P. M. Asbeck, and S. K. Kurtz, Appl. Phys. Lett. 35, 461 (1979)
   
5. M. K. Chun, L. Goldberg, and J. F. Weller, Appl. Phys. Lett. 1170, 53 (1988)
   
6. J. C. Baumert, P. Gunter, and H. Melchior, Opt. Commun. 48, 215 (1983)
   
7. L. Goldberg and M. K. Vhun, Appl. Phys. Lett. 55, 218 (1989)
   
8. G. J. Dixon, C. E. Tanner, and C. E. Wieman, Opt. Lett. 14, 731 (1989)
   
9. A. Hemmerich, D. H. McIntyre, C. Zimmermann, and T. W. Hansch, Opt. Lett. 15, 372 (1990)
   
10. T. Senoh, Y. Fujino. Y. Tanabe, M. Hirano, M. Ohtsu, and K. Nakagawa, Appl. Phys. Lett. 60, 1172 (1992)
    
11. C. H. Oh, S. G. Kim, J. S. Ahn, Y. C. Park, and P. S. Kim, J. Opt. Soc. Kor. 4, 206 (1993)
12. M. de Angelis, G. M. Tina, P. De Natale, C. Fort, G. Modugno, M. prevedelli, and C. Zimmermann, Appl. Phys. B 62, 333 (1996)
    
13. K. Ita, K. Kawamoto, and H. Momiji, J. Opt. Soc. Am. B 13, 1188 (1996)
    
14. P. Lodahl, J. L. Sorensen, and E. S. Polzik, Appl. Phys. B 64, 383 (1997)
    
15. A. Yariv and P. Yeh, Optical Waves in Crystals (John Wiley" Sons, New York, 1981)
16. B. Zysset, I. Biaggio, and P. Gunter, J. Opt. Soc. Am. B 9, 380 (1992)
    
17. I. Biaggio, P. Kerkoc, L. S. Wu, P. Gunter, and B. Zysset, J. Opt. Soc. Am. B 9, 507 (1992)
    
18. G. D. Boyd and D. A. Kleinman, J. Appl. Phys. 39, 3597 (1968)
    
19. H. S. Moon, J. B. Kim, J. D. Park, B. K. Kwon, H. Cho, and H. S. Lee, Appl. Opt. 35, 5402 (1996)