摘要 |
A short wavelength light source mainly comprises a semiconductor laser (30) for pumping a laser medium (61), a birefringence filter (40) for controlling or stabilizing the waveform by applying an optical feedback to the semiconductor laser (30) to feed back only light of specific wavelength, lens systems (33, 34) for focusing the pumping light (32), and an optical resonator (60) composed of a laser medium (61) formed of Nd:YAG doped with 1% of Nd and a nonlinear optical element (62) formed of KNbO3. The birefringence filter (40) is structured as a Lyot filter, and is composed of a birefringence element (41) made of 2mm thick non-doped YVO4, a polarizer (42), and a birefringence element (43) made of 4 mm thick non-doped YVO4. This constitution realizes a short wavelength light source achieving a single longitudinal mode oscillation while maintaining a high output, small in size, superior in efficiency, and excellent in wavelength stability. <IMAGE> |