| 摘要 |
An anamorphic optical collimator for laser diode having 5-lens elements of positive, positive, negative, positive, and positive optical power and designed to have an input aperture angle of up to ±22° in its meridianal section and up to ±6° in its sagittal section, large exit pupil, anamorphic coefficient equal to 4, angular divergence of collimated beam not exceeding 1 mrad, and the possibility of independently adjusting the angular divergences of the exit laser beam in the meridianal and sagittal planes of the optical collimator. The optical collimator comprises a first positive spherical lens element of a meniscus shape with its concave surface faced to laser diode, a second positive spherical lens element of a plane-convex shape, a third negative cylindrical lens element of a plane-concave shape, a fourth positive cylindrical lens element of a plane-convex shape, and a fifth positive lens element of a spherical plane-convex shape. The first three lens elements are mounted in a housing that may move along and rotate about the collimator's optical axis. This rotation allows the third lens element to rotate relative to the fourth lens element such that the angular divergence of the exit laser beam with respect to its meridianal and sagittal planes of the collimator may be independently adjusted. The exit pupil size of the optical collimator is chosen so as to provide a safe operating range of optical power densities with respect to the human eyes in cases of ocular exposure, even when the laser diode generates a beam with laser power as high as 100 mW. Furthermore, the optical collimator of the present invention minimizes beam aberration as much as possible while providing a collimated beam with an angular divergence of less than 1 mrad.
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