By using a concentrical configuration

a control arithmetic of adjusting the angular velocity and a mesh pattern of periodical latitude lines intersecting periodical latitude lines perpendicularly to ensure the writing spot scanning at different angular velocities in different latitudes and to keep the linear velocity and exposure dose invariable all the time in the laser direct writing system the invariable exposure dose laser direct writing mesh on the spherical substrate was realized. The key parameters such as the periods of gridding

the angular velocity and the arc length of the latitude lines were analyzed and the control program was designed. Several group experiments of laser direct writing mesh on the concave spherical substrate made of common glass with 60 mm were done at periods of 450~800 μm and linear velocity of 1~20 mm/s. After development and fixation

the error of gridding periods measured by micron level reading-microscope is within ±3%. Line width measured by AFM is less than 5 μm. The experiments results indicate that the concentrical configuration and control of steady light and angular velocity adjusting have ensured the exposure dose invariable

which make laser direct writing lines on the spherical substrate have good uniformity

steep and straight side walls parallel to each other for satisfying the design requirements.