OPTICAL HEAD AND SECONDARY HIGHER HARMONIC LIGHT SOURCE

摘要

PURPOSE:To produce an optical head with a short optical path by diffusing the secondary higher harmonic light beams outputted from a secondary higher harmonic generating means. CONSTITUTION:When a light beam 2 is made incident on a secondary higher harmonic generating means 4, a solid-state laser element 5 is excited for generation of a light beam 8. This beam 8 is defined as a basic wave when it is made incident on a nonlinear optical element 6. Then a light beam 9 is generated as a secondary higher harmonic of the basic wave. The beam 9 is amplified by a resonator consisting of a recess face 7a and an end face 5a and then partly transmitted through a reflector 7 as a light beam 10. Then the beam 9 emitted from the element 6 is turned into the diffused beams through a recess face 6a. At the same time, the beam 10 is also diffused. These diffused beams 10 are condensed by a condenser lens 11 so that a practical beam diameter is obtained with a short optical path.