The invention relates to a Lagrange
Gaussian beam Gouy phase parameter measuring method. In the prior art, an
optical path structure is complicated, restriction from
optical beam coherence is obtained and the measurement in an optical
system with high sensitivity and
high numerical aperture cannot be realized. According to the invention, the method comprises the following steps of: carrying out sector light shielding modulation on
beam wave front by using wave front
amplitude modulation technology of the Lagrange
Gaussian beam; and selecting beam radial parameters as zero, wherein a circular ring shaped
light spot with a gap is formed after beams are gathered; detecting the circular ring shaped
light spot with the gap by using a near field optical technology, wherein
azimuth angle parameter corresponding to the center of the gap is fundamental mode beam Gouy phase; and obtaining the Gouy phase of any Lagrange
Gaussian beam in different spreading positions through simple calculation. The Lagrange
Gaussian beam Gouy phase parameter measuring method provided by the invention has the characteristics of simplicity for realization, low requirement on structure positioning, high reliability, strong anti-interference performance, capability of realizing direct measurement with high sensitivity, capability of measuring the Gouy phase in the optical
system with
high numerical aperture, wide application range and the like.