| 摘要 |
<p>An optical rotator such as a Pechan rotator is arranged to rotate an image about a given axis. Light entering an input surface (AB) of the rotator is subjected to a number (e.g. five) of reflections, alternate reflections being total internal reflections and the intervening ones being mirror reflections. At least one of the surfaces, preferably one at which total internal reflection occurs, bears a layered polarising material (FE, HG) arranged to impart a defined polarisation effect as between light entering and exiting the rotator.</p> |
