The invention discloses an edge sensor for a
segmented mirror surface based on an interference principle, and a working method thereof. The edge sensor is characterized in that: an
optical flat or spherical lens is placed on a sub-mirror splicing seam of a measured
segmented mirror surface, the front surface of the
optical flat or spherical lens is completely anti-reflection, and the rear surfaceof the
optical flat or spherical lens is provided with a
coating film; a parallel
light source is arranged on the other side of a sub-mirror of the measured
segmented mirror surface and the optical flat or spherical lens, light rays vertically enter the optical flat or spherical lens by means of a semi-reflecting and semi-transmitting
prism and then part of the
light beam on the surface returns, the other part is reflected by the surface of the sub-mirror along an original path, the two beams of reflected light form interference fringes, the interference fringes enter a microscopic amplification imaging
system by means of the semi-reflecting and semi-transmitting
prism, and
target surface receiving and
digital imaging are carried out by means of a CCD or
CMOS detector, namely, the splicingerror of the adjacent sub-mirrors can be handled. The edge sensor prevents
starlight and
wavefront sensors from occupying and
wasting a limited high-imaging-quality
field of view of an optical
system, is low in price, stable in performance and not affected by environmental factors, and is suitable for detecting the splicing errors between the adjacent sub-mirrors of various optical segmented mirror surfaces.