The invention discloses a device for automatically detecting an incident angle in an
elliptical polarization measuring
system, which comprises a polarizing arm, a polarization detection arm and a substrate. The polarizing arm is used for producing detection light
waves in a polarization state and emitting the detection light
waves onto a sample; the polarization detection arm is used for performing polarization state re-modulation on the light
waves reflected by the sample and detecting
light energy; the substrate is used for supporting the polarizing arm and the polarization detection arm and is provided with a plurality of position detection switches; both the polarizing arm and the polarization detection arm are provided with triggering devices for triggering the position detection switches; and when the polarizing arm and the polarization detection arm rotate to different positions, the
triggering device arranged on the polarizing arm and the polarization detection arm change the states of the position detection switches to obtain an incident angle
signal and a reflecting angle
signal so as to realize position detections of the polarizing arm and the polarization detection arm and automatic detection of the incident angle. The device and a method for automatically detecting the incident angle in the
elliptical polarization measuring
system provided by the invention have the advantages of simple structure, easy implementation, low cost, rapidness, high efficiency,
automation and high reliability.