Study Of 2.52THz Gaussian Beam Shaping

In general, the spatial intensity distribution of the laser beam emitted by a laser is Gaussian, while in many practical applications, it is required that the spot has a unique distribution. Compared to visible light, Terahertz(THz) radiation has the advantage of being able to penetrate the organic matter, so it is very important t o research on THz Gaussian beam shaping.In order to shape the 2.52 THz Gaussian beam into a quiet zone, depengding on the two parameters of amplitude regulation coefficient and plane light incidence angle, seven different grating plates were designed based on the principle of holography, in this paper. The influences of amplitude regulation coefficient, plane light incidence angle and transmission distance on the range of quiet zone were studied. The optimal incident angle of the plane light and the optimal amplitude regulation coefficient were finded.In order to shape the 2.52 THz Gaussian beam into a ring beam, in this paper, depending on key design parameters, such as the ring thickness, the ring radius and the transmission distance, five different phase plates were designed based on the GS algorithm. The influences of multi order encoding phase plates, the ring thickness, the ring radius and the transmission distance on the shaping effect were studied. Finally, based on a CO2 continuous-wave THz laser system and a pyroelectric camera, Beam shaping experiments were carried out on the five two-step phase plates.