An optical path system that improves the shape of the spot and automatically adjusts the size of the spot

Abstract

The invention relates to a light path system capable of improving light spot patterns and automatically adjusting light spot size. The light path system capable of improving the light spot patterns and automatically adjusting the light spot size comprises a microlens array, an aspheric lens, a spatial filtering aperture, an imaging object lens and a scanning deflection module which are arranged on an excimer laser outlet in sequence. A shaping dodging device of an integrated box structure is formed by the microlens array, the aspheric lens and the spatial filtering aperture and moves horizontally between the excimer laser outlet and the imaging object lens, and the imaging object lens moves in parallel according to the horizontal moving distances of the microlens array, the aspheric lens and the spatial filtering aperture and according to the conjugation ratio calculated according to focal distances. The aspheric lens is adopted, spherical aberration is eliminated greatly, and the defocus of microlens imaging is weakened accordingly. Through the adoption of a secondary focusing method in a light path, the problems of the excessive-length of the light path, spatial filtering and image spot adjustability are solved, target light spots are clean and clear, and round light spots of any size within a certain range can be obtained according to the needs of surgery.

Description

technical field [0001] The invention relates to a design method of an external optical path, belonging to the field of optical path design. It can be applied to the external optical path design of the excimer laser, and can also be applied to the external optical path design based on the industrial processing of the single transverse mode laser. Background technique [0002] Excimer lasers are pulsed laser sources that emit deep ultraviolet light. The output size is typically a rectangular beam with a Gaussian intensity profile. On the surgical surface, a circular spot with relatively uniform energy distribution at each point needs to be obtained, so the optical path must have the functions of spot shaping and uniform energy. At the same time, because the bandwidth of the excimer light source is quite wide, dispersion occurs after being refracted by multiple mirrors, and finally a lot of stray light is generated around the target spot, so the function of spatial filtering ...

AI Technical Summary

Problems solved by technology

Since the wavelength band used is in the deep ultraviolet region, the transmittance and reflectivity of specially coated lenses in this band are relatively low, so it is very important to minimize the use of lenses and ensure the efficiency of energy transmission

[0003] Generally, a double-mirror structure is adopted, such as a double-aspheric mirror structure and a double-mirror structure, which can theoretically perform arbitrary wavefront transformation, but the devices used must be specially designed and customized; and the method of using array microlenses plus plano-convex lenses, although it can be effective Realize shaping, but because of the spherical aberration of the lens, the imaging of each micro-lens is defocused, making the boundary of the overlapping image spot blurred, and the length of the optical path outside the excimer therapeutic instrument is usually longer than 1m. If the focal length of the lens is too large, the defocusing phenomenon will be more serious obvious

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