| 摘要 |
An optical system has at least one dichroic Mangin mirror (12, 14) and a front-end optical subsystem (10) operate to emit an optical beam having at least a first color and a second color beams. The dichoric Mangin mirror is disposed along the optical paths of the first and second color beams. The dichroic Mangin mirror includes a first surface (12a or 14a) operate to transmit the first color beam only and reflects the second color beam, and a second surface (12b or 14b) to reflect the first color beam. Therefore, upon incident on the mirror, the second color beam is reflected, while the first color beam transmits through the first surface and is then reflected off from the second surface. Thereby, the first and second color beams can be focused at the same position which is referre as an achromatic system focus. |
