Patent ID: 6028873
Filing Date: 2000-02-22
Classification: G02F,H01S

Abstract:
An optical device comprising:a medium containing an impurity,having a first level, a second level and a third level in descending order of energy levels,and having first inherent transition probability between said first level and said second level, a second inherent transition probability between said first level and said third level and a third inherent transition probability between said second level and said third level;a resonator having a pair of mirrors arranged so as to interpose said medium, and having a plurality of resonant frequencies, a frequency of a first optical transition between said first level and said second level coinciding with one of said resonant frequencies of said resonator, a frequency of a second optical transition between said first level and said third level coinciding with one of said resonant frequencies of said resonator, a frequency of a third optical transition between said second level and said third level being out of phase with frequencies of said resonator; andan inputting means for a first coherent light having a wavelength essentially corresponding to said first optical transition and a second coherent light having a wavelength essentially corresponding to said second optical transition,wherein a transition probability of said first optical transition is higher than said first inherent transition probability,a transition probability of said second optical transition is higher than said second inherent transition probability,a transition probability of said third optical transition is lower than said third inherent transition probability,and said medium outputs a coherent output light having a wavelength essentially corresponding to said second coherent light.