| 摘要 |
<p>A laser cavity structure is disclosed which pertains to laser resonator geometries possessing circular symmetry, such as in the case of disk or spherical resonators. The term "Wagon Wheel Cavity" herein refers to circular optical cavities formed by VHF Bragg reflectors, wherein cavity size is sufficiently large to provide a multitude of modes at the desired wavelength using normal interference filters with relatively large index differences, so that such normal interference means will provide substantial reflectivity for an undesirably large number of modes, since the cavity sizes addressed herein are typically orders of magnitude greater in dimension than the optical wavelength for which they are intended. The disclosed invention utilizes very-high finesse Bragg reflector (VHF-BR) thin film reflectors of many layer pairs of very small refractive index difference, the VHF-BR formed on a surface of revolution, thereby forming an optical cavity. These dielectric reflectors are disposed so as to provide selection of preferred low order modes and suppression of parasitic modes, while providing a high cavity Q factor for preferred modes.</p> |
